political news

An Iranian nuclear scientist who claims he was abducted by CIA agents last year and taken to the US is on his way back to Tehran, Iran says.

On Monday evening Mr Amiri arrived at the Iranian Interests section of the Pakistani embassy in Washington, which handles Iranian affairs in the US capital, and asked to be repatriated.

While he was he was at the embassy he recorded an interview with a Danish commercial television production company, Atlantic Television News. The company said they did not pay money for this interview.

Mr Amiri claimed that he was kidnapped while on a pilgrimage to Saudi Arabia and was later "psychologically tortured" by the US.

The US state department has insisted he was in the US of his own free will.

If Iran decides to go for nuclear weapons, the US may not be able to permanently stop this from happening unless it is willing to occupy the country.

This is the candid conclusion of one US general testifying in front of the Senate but one that seems to have gone mostly unnoticed amid a flurry of statements on Iran over the past few days in Washington.

Gen James Cartwright, one of America's top uniformed officers, slowly edged towards that conclusion during a Senate testimony last week, underscoring the difficult choices facing the Obama administration as it weighs what do about Iran.

Since the US would probably be extremely apprehensive about even considering putting boots on the ground in Iran, the statement raises a key question - while the Obama administration publicly maintains that it will not allow Iran's current leaders to acquire nuclear weapons, is it privately discussing how to live with a nuclear Iran?

The military is averse to any action against Iran and Adm Mike Mullen, the chairman of the Joint Chiefs of Staff, said a military strike would be 'his last option" and has warned of the unintended consequences of such a strike.

One of those consequences could be a boost in the life expentancy of the Iranian leadership.

If Iran comes under attack from the outside, Iranians will likely rally around their leaders or be forced to do so.

This would put an end to any internal dissent and delay the prospect of internal pressure for change. After all, a different Iranian leadership that cooperates more with the international community is another way of allaying concerns about Iranian nuclear ambitions.

But during the Senate testimony, which also featured the state department's No 3 official, William Burns, the senators questioning the panel also established that UN sanctions would probably not be tough enough to really have an impact on Tehran.

'Nuclear virginity'

Senator Jack Reed, a Democrat from Rhode Island, then asked Gen Cartwright whether the "military approach was a magic wand".

Gen Cartwright, the vice-chairman of the Joint Chiefs of Staff, acknowledged it was not, adding that military action alone was unlikely to be decisive.

Senator Reed prodded further, getting the general to agree that a military strike would only delay Iran obtaining a nuclear weapon if Tehran decided to go nuclear.

The senator then went further, asking whether the only way to absolutely end any potential Iranian nuclear weapon programme "was to physically occupy their country and disestablish their nuclear facilities?"

The general answered: "Absent some other unknown calculus that would go on, that's a fair conclusion."

Graham Allison from the Belfer Center for Science and International Affairs at the Harvard Kennedy School said it was very difficult to stop a state determined to get the nuclear bomb if they decided they wanted it.

"Iran has lost its nuclear virginity, and it's a fact that can't be erased," said Mr Allison.

A lot of the focus in recent days has been on a leaked memo sent by Defence Secretary Robert Gates, which apparently lays out what steps to take against Iran's nuclear programme if it ignores international sanctions.

The memo was described by the New York Times as a wake up call for the administration, but Mr Gates said it was meant "to contribute to an orderly and timely decision process making".

Either way, the Obama administration is considering the options it has if sanctions do not have the intended impact. But critics say that is not enough.

'So far, no action'

"We have not done anything that would in any way be viewed effective. I didn't need a secret memo from Mr Gates to ascertain that," said Republican Senator John McCain on Fox News over the weekend.

Senator McCain was also on the Senate armed services committee questioning Gen Cartwright.

"The list goes on and on of the threats that we have made to the Iranians and so far no action" said Senator McCain.

"George Schultz, my favourite secretary of state in all the world, once said his marine drill instructor told him, never point a gun at somebody unless you're ready to pull the trigger. We keep pointing the gun. We haven't pulled a single trigger yet, and it's about time that we did."

Senator McCain was probably also speaking figuratively about crippling sanctions.

"The ripple effects in the region of a military strike against Iran would be ugly," said one senior US official speaking on the condition of anonymity because of the sensitivity of the issue.

But he added that the longer it took to put sanctions in place, the more the risk of a military strike increased.

"The closer you get to the end of 2010, the temptation to act gets greater," said the official, who seemed to implicitly indicate it was Israel that would mostly be tempted to act.

'Embargo'

This would still only delay any Iranian plans to pursue nuclear weapons.

Ideally, the Obama administration would like to convince Tehran that a nuclear weapon will not make it more powerful or more secure.

But without a change inside Iran, that argument is unlikely to have much weight because Iran does believe that its nuclear ambitions give it added clout in the region.

"If the international community was prepared to impose crippling sanctions, embargoing imports of gasoline and exports of oil, if it strangles Iran - Iran might recalculate," said Mr Allison from the Belfer Center.

"This is a regime that has survival at the top of its list. But imposing such sanctions without the support of Russia and China is impossible."

So with the US neither able to impose crippling sanctions nor really eager to take the tough military action needed to permanently disable Iran's nuclear facilities, Washington's only options seem to be to either accept a nuclear Iran or find ways to continuously disrupt and slow down Iran's nuclear ambitions.

Iran has been subjected to three rounds of United Nations Security Council sanctions in relation to its nuclear programme.

In spite of this, it has continued its uranium enrichment operations and there is growing pressure for sanctions to be tightened further.

In March 2006, the issue was discussed at the UN Security Council, which called for a report by the IAEA to establish Iran's compliance with the terms of the nuclear non-proliferation treaty (NPT).

The treaty allows for the use of nuclear technology for peaceful energy purposes, as long as countries can demonstrate that their programmes are not being used for the development of nuclear weapons.

In July 2006, the Security Council said it was "seriously concerned" that the IAEA was unable to provide assurances about Iran's undeclared nuclear material. It demanded that Iran "suspend all enrichment-related and reprocessing activities, including research and development", giving it one month to do so. Failing that, it would face the possibility of economic and diplomatic sanctions.

Iran asserted that its nuclear programme was for civilian use permitted by the NPT. On this basis it said it rejected the validity of the Security Council's calls. It claimed that while subscribers to the NPT were being punished, those who had not signed up to the agreement were being rewarded by generous nuclear cooperation agreements.

The deadline for Iranian compliance with the Security Council's demands passed without being heeded. In December 2006, the Council unanimously adopted Resolution 1737 (2006).

This called on states to block Iran's import and export of "sensitive nuclear material and equipment" and to freeze the financial assets of those involved in Iran's nuclear activities.

The Council decided that all countries should prevent the supply or sale of equipment and technology that would aid Iran's nuclear programme in any way.

Arms

With Iran's nuclear programme ongoing, in March 2007 the Security Council voted to toughen sanctions. It banned all of Iran'S arms exports. It also froze the assets and restricted the travel of people it deemed involved in the nuclear programme.

Financial and trade

Further restrictions imposed in March 2008 encouraged scrutiny of the dealings of Iranian banks.

It also called upon countries to inspect cargo planes and ships entering or leaving Iran if there were "reasonable grounds" to believe they were goods prohibited by previous resolutions.

But it would take another three to five years to actually produce a "deliverable weapon that is usable," a senior general told Congress.

The warning came as Iran said it had produced its first significant batch of more highly-enriched uranium.

Meanwhile, negotiations have resumed at the UN on a possible Iran sanctions resolution over its nuclear programme.

Speaking to the US Senate Armed Services Committee, two military officials said if Iran's leadership decided to, enough highly-enriched uranium could be produced in one year to build a single atomic weapon.

Lt Gen Ronald Burgess, the director of the Defense Intelligence Agency, said the centrifuges at Iran's Natanz nuclear plant were producing low-enriched uranium and were not yet being used to produce the more highly-enriched uranium needed for weapons.

Gen James Cartwright told the committee that if Iran did move to producing the 90%-enriched uranium needed for a bomb, more time would be needed to actually build and test the weapon.

"Experience says it is going to take you three to five years" to reach the stage of having a "deliverable weapon that is usable... something that can actually create a detonation, an explosion that would be considered a nuclear weapon."

Iran's nuclear chief, Ali Akbar Salehi, said on Wednesday that 5kg (11 lbs) of uranium had been enriched at Natanz from 3.5% to the 20% needed to fuel a research reactor in Tehran.

President Mahmoud Ahmadinejad ordered the further enrichment to begin in February after talks on a UN-brokered proposal for Iran to send its uranium abroad for enrichment broke down.

Iran has defied five UN resolutions demanding that it stop enriching uranium.

Some western nations, led by the US, fear Iran may be trying to develop the capacity to produce nuclear weapons.

Iran says its nuclear programme is solely for civilian purposes.

US moves to gather support for a fourth round of sanctions against Iran over its nuclear work were bolstered by the nuclear security summit held in Washington earlier this week, says the BBC's Barbara Plett at the UN in New York.

Ambassadors from the US, Britain, France, Germany, China and Russia have resumed negotiations at the UN on possible sanctions.

Diplomats say China and Russia want something "much much weaker, much much narrower" than the other countries and China has not publicly said it would support sanctions, our correspondent reports.

The UN ambassadors are discussing a text prepared by the Americans outlining possible measures in five areas: energy, shipping, finance, an arms embargo and punishing members of Iran's Revolutionary Guard Corps, which oversees the country's nuclear programme, our correspondent adds.

Talks on the sanctions are expected to run for a number of weeks yet.

Iran has signed an agreement to send uranium abroad for enrichment after mediation talks in Tehran with Turkish and Brazilian leaders.

Correspondents say the plan could revive a UN-backed proposal and may ward off another round of sanctions.

But the BBC's Tehran correspondent says the deal will be viewed with scepticism in Western capitals, as Iran says it will continue enriching uranium.

Meanwhile, France has announced progress at the UN on fresh sanctions.

AFP news agency reported that Israeli officials were accusing Iran of manipulating Brazil and Turkey to stave off sanctions.

The West has long suspected that Iran's nuclear programme is aimed at making weapons - a charge Tehran denies.

Progress made?

Under the deal, Iran's foreign ministry said it was ready to ship 1,200kg (2,645lb) of low-enriched uranium to Turkey, in return for fuel for a research reactor.

The deal does not address the central nuclear issues dealt with by successive UN Security Council resolutions - namely Iran's refusal to halt its enrichment programme and address questions about its past nuclear activities.

The US reacted by saying it still had serious concerns over Iran's nuclear programme, although it did not reject the agreement.

It said the Iranian government "must demonstrate through deeds - and not simply words - its willingness to live up to international obligations or face consequences, including sanctions".

"While it would be a positive step for Iran to transfer low-enriched uranium off of its soil as it agreed to do last October, Iran said today that it would continue its 20% enrichment, which is a direct violation of UN Security Council resolutions," said a White House statement.

Russia welcomed the deal, although President Dmitry Medvedev said further talks were needed on Iran's nuclear programme.

During a trip to Ukraine Mr Medvedev said the fact that Iran apparently still intended to continue its own uranium enrichment would continue to concern the international community.

French Foreign Minister Bernard Kouchner said there had been "some important progress" in talks at the Security Council on fresh sanctions against Tehran.

The UK, for its part, said work on a resolution about imposing new sanctions on Iran would continue until Tehran showed its intentions were peaceful.

The German government said that nothing could replace a deal between Iran and the UN's nuclear watchdog, the IAEA.

Iran's President Mahmoud Ahmadinejad called on world leaders for new talks "with Iran based on honesty, justice and mutual respect".

The EU's high representative for foreign affairs, Baroness Ashton, was ready to meet the Iranian authorities to find a "full and complete" solution to the stand-off, her spokesman said.

'Negotiating ploy?'

Turkish Prime Minister Recep Tayyip Erdogan and Brazil's President Luiz Inacio Lula da Silva were at the talks in Tehran with Mr Ahmadinejad.

Iranian foreign ministry spokesman Ramin Mehmanparast said 1,200kg of low-enriched uranium would be shipped to Turkey, and that Iran would notify the IAEA "within a week".

Under the deal, Iran has said it is prepared to move its uranium within a month of its approval by the so-called Vienna Group (US, Russia, France and the IAEA).

In return, Iran says it expects to receive 120kg of more highly enriched uranium (20%) - a purity well below that used in the manufacture of nuclear weapons - within a year.

If the deadline is not met, Iran says Turkey "will return swiftly and unconditionally Iran's low-enriched uranium".

BBC Tehran correspondent Jon Leyne, in London, says the agreement does not make clear whether Iran's low-grade uranium will be used to make the new fuel or just held as a kind of security deposit.

Our correspondent says Western governments will fear this is just a negotiating ploy designed to delay new sanctions.

Crucially, Turkey and Brazil are both on the UN Security Council, and so have a vote on those sanctions.

The Turkish Foreign Minister, Ahmet Davutoglu, who spent 18 hours hammering out the deal with his Brazilian and Iranian counterparts, said there was now no need for more sanctions against Iran.

"The swap deal shows that Tehran wants to open a constructive path... there is no more ground for new sanctions and pressures," he said.

'Last chance'

The US is in the final stages of negotiating a fourth sanctions package with other UN Security Council members.

This new deal will be examined in great detail and with a high degree of scepticism in foreign capitals, our correspondent says.

Iran backed out of a similar proposal last October citing disagreement about the details of the deal, which included a simultaneous swap, something the IAEA said was not feasible.

Iran's stocks are now thought to be much larger than the 1,200kg covered by the new agreement.

Both Russia and the US say the talks represent Iran's last chance to avoid harsher sanctions.

Iran has been mounting a big diplomatic effort to prevent new UN sanctions; its foreign minister has visited all 15 members of the Security Council.

As pressure grows on Iran over its nuclear programme, there is evidence that behind the scenes, the United States has stepped up its push to isolate Tehran economically.

In recent weeks a number of countries and companies have cut back on their imports of Iranian crude oil. They include some of Iran's most important trading partners: China, Japan and India.

At the same time more companies have stopped supplying Iran with refined petroleum. Because of a shortage of refining capacity, Iran relies on such imports to meet domestic demand.

The move was explained in unusually blunt terms this week by a senior US official.

William Burns, US Under-Secretary of State, told a Congressional committee: "What we've been doing is to try to use every lever that we already have at our disposal to encourage foreign companies, foreign entities to cut their ties with the Iranian economy."

"The squeeze is on," said Kate Dorian, Dubai bureau chief for the energy analysts Platts. "Very few people are willing to deal with Iran directly."

Even the head of the Iranian union of oil exporters, Hamid Hoseyni, has acknowledged there has been a cut in exports of Iranian oil to China, Japan and India - all key customers - though he said overall Iranian exports had not been affected.

The pressure on Iran comes as the United States leads a push for new sanctions on Iran over its nuclear programme.

President Obama has said he expects the measures to be agreed at the UN Security Council "this spring". Spring officially turns to summer in the United States on 21 June, so that gives American diplomats just over two months to conclude their negotiations.

Production down?

Hard figures are difficult to confirm, and traders point out that Iran may simply have been over-pricing its oil. Iranian oil also suffers from being very "heavy" so it can be more difficult to sell when the market is over-supplied.

Platts energy analysts reckon that Iranian output is holding up at 3.76 million barrels a day, well above their Opec target. But others use Iranian government figures to paint a much less rosy picture, suggesting Iran is producing not much more than 3.5 million barrels a day.

Mr Hoseyni of the Iranian union of oil exporters is quoted as saying that China has cut imports from Iran from 400,000 barrels a day to 200,000 barrels a day.

Japan is also reported to have cut back on imports of Iranian oil. And the Indian company Reliance has also reduced or ended its dealings with Iran.

Reliance was an important customer for Iranian oil because its huge refinery was particularly suited to processing Iran's output of heavy or very heavy crude.

According to the semi-official Iranian news agency, ISNA, Reliance was buying 90 to 100,000 barrels of oil a day, or 2.4% of Iranian output.

Reliance was also one of the biggest suppliers of refined petroleum to Iran, and it is one of a number of petrol suppliers who appear to have succumbed to political pressure to pull out of trading with Iran, or at least cut back on the business.

Others include the Russian company, Lukoil, BP, Shell, Trafigura, Vitol, Glencore and IPG.

Dependence

Iran's dependence on imported petroleum has often been identified as one of its weaknesses. Iranians love their cars, and when petrol rationing was introduced in the summer of 2007, there was violence on the streets.

The US congress has been pressing President Obama to introduce sanctions on petrol exports to Iran. So far Mr Obama has been reluctant to go ahead, at least with any formal measure.

Some analysts point out that Iran has alternative suppliers who can fill the gaps. The analysts PFC say that Turkmenistan, Venezuela, Kuwait and Malaysia have all been willing to make up the shortfall.

A Chinese tanker this week was reported to be preparing to carry a major shipment of petrol to Iran. And Total of France is also still selling petrol to Iran.

Total's CEO has said that his company has received "indirect" messages from Washington about such sales, though not a direct request to stop.

At the very least, though, the pressure means Iran may have to pay a premium for its petrol imports, even if they can be re-sourced through flags of convenience.

The pressure on Iran is an interesting study in how the United States uses its economic might to leverage political influence.

Lukoil, for example, although it is a Russia company, also has major US shareholders, and a chain of petrol stations in the United States. Reliance of India also has significant interests in America as well.

US pressure

For some time, American officials have been using these levers to curtail financial transactions with Iran.

European banks have received a simple message: they can either trade with Iran, or with the United States, not both.

US treasury officials have made a least two visits to Europe to underline the message.

As a result it is becoming increasingly difficult to transfer money to and from Iran, and it is almost impossible to obtain letters of credit, another possible reason for the reduction in the oil trade.

The United States has also been using its alliance with Saudi Arabia to help suggest alternative sources of oil supply for Asian countries who make up some of Iran's most important customers.

There's also a wider push to encourage non-American companies to stop doing business with Iran.

The German company Daimler announced this week that it was pulling out of Iran. The German Chancellor, Angela Merkel, has reportedly agreed to discourage trade between German companies and Iran, so long as Washington does not use public pressure on the issue.

Austria, however, still actively and openly promotes trade with the Islamic Republic.

Worker unrest

The Obama administration says it wants new UN sanctions to target the nuclear programme, and specifically the Revolutionary Guards, who occupy a growing position of power within the Islamic Republic.

American officials argue that they want to hurt the leadership and not the Iranian people. There's also a fear that the Iranian government could blame sanctions for its self-created economic problems.

In any case, Washington would be unlikely to secure agreement at the United Nations for the sort of measures it is pressing informally.

But the behind the scenes pressure to isolate Iran economically seems designed to produce more widespread economic problems, and perhaps even to provoke worker unrest.

Exile groups have been giving many details of layoffs imposed on Iranian workers, and also numerous protests over unpaid wages.

Those are all indications that President Mahmoud Ahmadinejad's government is facing growing economic pressure, at a time when its legitimacy continues to be challenged following the disputed election last summer.

To date, though, worker unrest has not risen to the point that it appears to pose a major threat to the government.

Nevertheless economic pressure on the Iranian government, combined with mismanagement and under-investment, and growing domestic demand, does appear to mean that Iran is struggling to maintain the current level of oil export earnings, a critical lifeline for the government.

Internal division

According to one western analysis of figures from the Iranian central bank, those lower oil earnings are seriously depleting Iranian foreign currency reserves. Mr Ahmadinejad's profligate spending have made things worse as well.

Under this assessment reserves could reach a critical level within a year, forcing the government either to devalue the Iranian rial, or to make other drastic policy decisions.

One of the biggest problems for Mr Ahmadinejad's government is that it is severely weakened since the disputed election last summer. It has often appeared incapable of decisive action, sometimes close to paralysis.

The divisions are not so much between government and opposition, as those between different factions of conservatives. Mr Ahmadinejad himself is deeply unpopular even amongst many fellow conservatives. He is not owed many favours.

The effect of that has been seen most clearly in the dramatic swings in policy over the nuclear issue. But it is also causing big problems in the management of the economy.

One response to the financial crisis might be to cut subsidies, particularly petrol subsidies, something Mr Ahmadinejad has been trying to do.

But the Iranian president has been entangled in a long running dispute with the parliament over the extent of subsidy reform, and there's no sign of an early resolution.

This American economic pressure appears aimed to encourage Mr Ahmadinejad to come to the table over the nuclear issue. So far there is little sign of this bearing fruit. And there is little sign that President Ahmadinejad's government even has the authority to offer a deal over the nuclear question, even if it wanted to.

But Western policy makers could also be playing a longer game. They may be hoping that in the longer term, economic pressure could undermine Mr Ahmadinejad's position, or even eventually threaten the very existence of the Islamic Republic itself.

The allegation came days after the US enacted unilateral sanctions over Iran's nuclear programme, to penalise foreign companies trading with Tehran.

Britain said it was not aware of any refusal to refuel Iranian planes, and Germany stressed there was no ban.

Oil firms contacted by the BBC said they could not comment on individual contracts.

Tehran says its nuclear industry is for peaceful purposes but Western powers fear it is trying to develop a bomb.

"Since last week, our planes have been refused fuel at airports in Britain, Germany and UAE because of the sanctions imposed by America," Mehdi Aliyari, secretary of the Iranian Airlines Union, told Iranian media.

He said the national carrier Iran Air and a private airline, Mahan Air, had both run into refuelling problems.

"Refusing to provide fuel to Iranian passenger planes by these countries is a violation of international conventions," he added.

Iranian lawmaker Heshmatollah Falahatpisheh said Iran would retaliate.

"Iran will do the same to ships and planes of those countries that cause problems for us," Iran's Isna news agency quoted him as saying.

A spokeswoman for the Abu Dhabi Airports Company (ADAC), which manages the airports in the UAE cities of Abu Dhabi and Al Ain, told Reuters news agency the company was continuing to refuel Iranian jets.

"We have contracts with Iranian passenger flights and continue to allow refuelling," she added.

But AFP news agency quoted "a source close to the aviation sector in the UAE" as saying there had been a problem with an unnamed international fuel supplier.

"A servicing company which provides fuelling at several airports around the world has refused to provide Iranian planes with fuel, including at UAE terminals," the source said on condition of anonymity.

A spokesman for the UK's Civil Aviation Authority told the BBC any move to withhold fuel would be down to individual fuel companies.

Germany's transport ministry said the refuelling of Iranian planes was not banned under EU or UN sanctions but it would not comment on whether any individual providers were refusing to fuel Iranian aircraft.

The US sanctions prohibit the sale or provision to Iran of refined petroleum products worth more than $5m (£3.3m) over a year.

Paul Reynolds, world affairs correspondent for the BBC News website, said it might be that fuel companies are worried that their sales over a year might add up to $5m, in which case they could face a possible ban on doing business in the US.

An Iranian aviation official said Iranian airliners were filling up with as much fuel as possible inside Iran.

But they were also having to refuel in countries along their route not imposing a ban, a move which the official said was doubling costs.

The new US sanctions were signed into law by President Barack Obama last week.

Last month, the UN Security Council voted to impose a fourth round of sanctions on Tehran for failing to halt its nuclear enrichment programme.

The defendants face charges of spying for foreigners, cooperating with Israel and "corruption on Earth", a charge which carries the death sentence.

The Bahai religion is banned by the Islamic revolutionary leadership of Iran which considers it heretical.

The group have been held since their arrest in 2008. The US government has condemned the trial, expressing concern about Iran's treatment of Bahais.

"The United States strongly condemns the Iranian government's decision to commence the espionage trial against seven leaders of the Iranian Bahai community," said US State Department spokesman PJ Crowley.

"We are deeply concerned about Iran's ongoing persecution of Bahais and treatment of other members of religious minorities who continue to be targeted solely on the basis of their beliefs," Mr Crowley added.

The Iranian move came only days after President Ahmadinejad spoke positively of a deal under which the further enrichment would be done abroad.

There are still no answers to the questions: Does Iran intend to build a nuclear device one day?

Is it simply acquiring some of the know-how so that it could do so?

Is it, as it says, just developing the peaceful use of nuclear power, exercising its rights under the Non-Proliferation Treaty (though this is for the moment superseded by the demands of the Security Council and the UN's nuclear watchdog the IAEA that it stop all enrichment activities)?

Or is it using its nuclear programme as a rallying-cry for the regime and to increase its international impact?

As is so often the case with Iran, it has, with this latest move, increased its resistance but has fallen short of reaching the significant red line of enriching to weapons-grade standard.

Medical reactor

It has said that it will raise the level of its uranium enrichment only to a level not suitable for a nuclear weapon and only for a particular purpose.

Specifically, it has said it will take some of the uranium it has enriched to the 3.5% level needed for nuclear power station fuel and will further enrich it to 20%, but not to the 90% needed for a useable nuclear bomb. One assumes it can do this, though the IAEA will have to verify it.

This plan, it says, would give it fuel to power a small nuclear reactor producing medical isotopes. The reactor has been operating in Tehran since 1968 (it was installed for the Shah by the Americans), but is running short of fuel. The current fuel for the reactor comes from Argentina.

Last year Iran suggested getting more fuel from abroad but was instead offered a deal under which its low-enriched uranium was taken to Russia and France for conversion into the necessary fuel rods and returned. The idea was to get the bulk of the uranium out of Iran (it is currently simply stored) and allow time for negotiations.

Iran has countered by offering to swap batches of low-enriched uranium for the fuel rods but on its own soil. It is afraid that otherwise it might not get back its stockpile, or any fuel rods, at all. Despite some promising noises, this deal remains undone. Iran still says it would not need to do the extra enriching if it got fuel from elsewhere.

Arguments

In Iran's favour, it can be stated that it does have a problem with the Tehran reactor and that it has repeatedly said that it will not build a bomb.

The 20% enrichment, it also says, will be done at the Natanz plant, which is under IAEA monitoring.

Against that, it is still defying the United Nations Security Council on total enrichment suspension and refuses to enter into talks about a long-term way of ensuring that its intentions are peaceful.

There is an added loose-end this time.

It is not clear how Iran could convert - and therefore why it is doing so - the 20% enriched uranium into fuel rods for the Tehran reactor as only France and Argentina can do that at the moment.

Sanctions debate

All this leaves the countries negotiating with Iran - the US, Russia, China, Britain, France and Germany - split as to how to react.

The US, Britain, France and Germany want to increase sanctions, and aim them specifically at those involved in the nuclear work, but China has said no for the moment and Russia is uncertain.

The hope is that a policy can be agreed by the time of a nuclear Non-Proliferation Treaty review conference in May.

Israel seems willing at the moment to wait to see how the diplomacy works out and the US does not appear keen on military action.

The chairman of the joint chiefs of staff, Admiral Michael Mullen, has recently stressed not only the instability that would result from Iran acquiring nuclear weapons but the instability that would result from an attack on Iran.

The measures, which penalise foreign companies that trade with Iran, were overwhelmingly approved by US Congress last week.

Mr Obama said the sanctions would strike "at the heart" of Iran's ability to fund and develop nuclear programmes.

Iran says its nuclear industry is for peaceful purposes; the West disagrees.

The bill targets those firms that supply Iran's Revolutionary Guards or contribute to the country's energy industry, including foreign companies that provide finance, insurance, or shipping services.

"There should be no doubt - the United States and the international community are determined to prevent Iran from acquiring nuclear weapons."

Mr Obama noted that Iran had rejected the offer of dialogue and engagement he had made on taking office last year.

"To date, Iran has chosen the path of defiance," he said. "That is why we have steadily built a broader and deeper coalition of nations to pressure the Iranian government."

Tehran denies seeking to acquire nuclear weapons.

Last month, the UN Security Council voted to impose a fourth round of sanctions on Tehran for failing to halt its nuclear enrichment programme.

They include tighter finance curbs and an expanded arms embargo, but not the crippling sanctions the US had wanted.

Iran's President Mahmoud Ahmadinejad dismissed those sanctions as a "used handkerchief" fit for the dustbin.

Three earlier rounds of UN sanctions have blocked trade of "sensitive nuclear material", frozen the financial assets of those involved in Iran's nuclear activities, banned all of Iran's arms exports and encouraged scrutiny of the dealings of Iranian banks.

A man who says he is an Iranian nuclear scientist claims to have escaped after being abducted by US agents.

In a video shown on Iranian state TV, he says he has escaped in the US state of Virginia and is now on the run.

Mr Amiri disappeared a year ago while undertaking the Hajj in Saudi Arabia.

Two videos purportedly showing him surfaced three weeks ago. One said he had been kidnapped, the other that he was living freely in Arizona.

The US has strenuously denied abducting him, but ABC News reported in March that Mr Amiri had defected and was helping the CIA compile intelligence on Iran's controversial nuclear weapons programme.

The state department has refused to say whether he is in the US.

In the new video, broadcast on Tuesday, a man claiming to be the missing scientist says: "I, Shahram Amiri, am a national of the Islamic Republic of Iran and a few minutes ago I succeeded in escaping US security agents in Virginia.

"Presently, I am producing this video in a safe place. I could be re-arrested at any time."

The man says the video broadcast earlier this month - in which someone claiming to be Mr Amiri says he was kidnapped by Saudi and US agents, tortured, forced to say he had defected and was living in Tucson, Arizona - is "completely authentic and there are no fabrications in it.

"The second video which was published on YouTube by the US government, where I have said that I am free and want to continue my education here, is not true and is a complete fabrication.

"I am not free here and I am not permitted to contact my family. If something happens and I do not return home alive, the US government will be responsible."

He finishes the video by urging Iranian officials and human rights organisations to "put pressure on the US government for my release and return".

"I was not prepared to betray my country under any kind of threats or bribery by the US government," he adds.

A US official told the AFP news agency the allegations were "ludicrous".

Russian President Dmitry Medvedev has criticised the unilateral US and EU sanctions on Iran that go beyond those approved by the UN Security Council.

He said Russia "did not agree" to any separate sanctions when it backed a joint UN resolution last week.

Meanwhile, Pentagon chief Robert Gates said US intelligence showed that Iran could be able to attack Europe with "scores" of missiles by 2020.

He added that Russia seemed to have a "schizophrenic" approach to Iran.

Moscow viewed Iran as a threat, but still pursued commercial ties with it, he told a US senate hearing in Washington.

Western powers suspect Iran is seeking nuclear weapons - which Tehran denies.

In an interview that ran on Thursday, the Russian leader criticised the EU and US for acting unilaterally.

"We didn't agree to this when we discussed the joint resolution at the UN," Mr Medvedev told the Wall Street Journal.

Russia this month agreed to back a fourth round of UN sanctions against Tehran, following months of US-led diplomacy.

The United States is expanding its sanctions against Iran because of concerns about its nuclear ambitions.

Washington said the individuals and institutions targeted were helping Iran to develop its nuclear programme.

This is the first step in implementing sanctions adopted by the UN Security Council last week.

Those blacklisted include Iran's Post Bank, Defence Minister Ahmad Vahidi and the air force and missile command of the Revolutionary Guard Corps.

Western powers accuse Iran of seeking to develop nuclear weapons - a charge Iran strongly denies.

The US sanctions prohibit any American business or individual from trading with those named on the blacklist. The sanctions also freeze any assets they may have under US jurisdiction.

"We will continue to target Iran's support for terrorist organisations, we will continue to focus on Iran's Revolutionary Guard, and we will continue to expose Iran's efforts to evade international sanctions," US Treasury Secretary Timothy Geithner told a White House news briefing.

Also on the list is a front company for the national shipping line, which is run by the Revolutionary Guards.

The Treasury has designated 27 new ships and has updated entries for 71 others whose names had been changed.

The designation of Post Bank brings to 16 the total number of Iranian banks under sanctions. The US Treasury says Post Bank is a front for Bank Sepah, which was designated in 2007 for providing financial services to the Iranian missile industry.

Last week, Iran's President Mahmoud Ahmadinejad dismissed the UN sanctions as "a used handkerchief" fit for the dustbin.

The European Union, which has been working closely with Washington, will decide on its own sanctions at a summit on Thursday.

The EU's proposed sanctions go further than the UN, targeting the oil and gas industry.

EU countries such as Germany and Italy have become important trading partners for Iran, but the EU is becoming increasingly concerned that Iran may be pursuing nuclear weapons.