Iran agreed on Monday to ship much of its low enriched uranium abroad in a nuclear fuel swap deal backed by Turkey and Brazil, but the United States said moves for toughened sanctions would still go ahead.

The accord, which commits Iran to depositing 1,200 kilograms (2,640 pounds) of low enriched uranium (LEU) in Turkey in return for fuel for a research reactor, was signed by the foreign ministers of Iran, Turkey and Brazil.

Tehran, already under three sets of UN sanctions over its defiant nuclear drive, touted the agreement as a goodwill gesture that paves the way for a resumption of talks with world powers.

But the United States said it would not halt or slow its drive for toughened sanctions against the Islamic republic.

"It does not change the steps that we are taking to hold Iran responsible for its obligations, including sanctions," White House spokesman Robert Gibbs said.

Gibbs, who had earlier issued a written statement expressing "serious concerns" about the deal, said that if Tehran lived up to the new pact it would represent "some progress."

But even if that took place, Gibbs said Washington had concerns about the "overall thrust" of the nuclear programme and the fact Tehran said it would continue enriching uranium to 20 percent.

State Department spokesman Philip Crowley said: "There are those who might characterize this as a breakthrough. I think we remain skeptical that this represents anything fundamentally new."

However, he said US officials were still evaluating the accord, and planned to consult with its international partners in the coming days, including with Brazil and Turkey.

Turkish Foreign Minister Ahmed Davutoglu said there was "no need" for further UN sanctions in the light of the deal as his country and Brazil "have made guarantees and the low enriched uranium will remain in Turkey."

Brazilian President Luiz Inacio Lula da Silva, a driving force behind the accord, said: "Diplomacy emerged victorious today. It showed that it is possible to build peace and development with dialogue."

Monday's signing came after three-way talks in Tehran by President Mahmoud Ahmadinejad, Lula and Turkish Prime Minister Recep Tayyip Erdogan.

Lula and Erdogan are due to meet again on Tuesday in Madrid on the sidelines of the EU-Latin America summit, according to the Brazilian president's agenda.

EU foreign affairs chief Catherine Ashton said Monday's accord only "partly" responds to the demands of the International Atomic Energy Agency (IAEA), which has been probing Iran's nuclear programme for years.

The IAEA said it had received the text of the joint declaration by Iran, Brazil and Turkey, but was now expecting Tehran to notify it directly of what commitments it had undertaken.

"In line with what was stated there, we are now expecting written notification from Iran that it agrees with the relevant provisions included in the declaration," said spokeswoman Gill Tudor.

Ashton said an IAEA offer in October for Iran to have its uranium enriched abroad recognised the right for civil nuclear power, but was "not an attempt to address the underlying issue... which is the nuclear weapon intention issue."

Russian President Dmitry Medvedev had previously welcomed the agreement but said further talks were needed.

"What was done by our colleagues needs to be welcomed. This is the politics of a diplomatic solution," he said. "We need to have consultations with all the parties, including Iran, and then determine what to do next."

Iran had said the signing meant the ball was now in the court of Western powers, and Ahmadinejad called for fresh talks over Tehran's nuclear programme.

"I hope the 5+1 (UN Security Council permanent members plus Germany) enter talks with honesty, respect and fairness and heed the great work started in Tehran," the official IRNA news agency quoted him as saying.

Iran's arch-foe Israel -- the sole if undeclared nuclear-armed power in the Middle East -- was quick to accuse Tehran of manipulating Turkey and Brazil and seeking to buy time in the long-running nuclear standoff.

Britain also expressed reservations. "Iran's actions remain a serious cause for concern," junior foreign minister Alistair Burt said.

Germany said nothing could replace the IAEA deal that envisages Iran's 3.5 percent LEU being sent to Russia and France for enrichment to 20 percent and then returned as fuel for the Tehran reactor.

The UN-brokered offer appeared to be a breakthrough in long-stalled discussions over the refueling of the Tehran research reactor that makes radioisotopes for cancer treatment.

But Iran has so far stalled on the deal the IAEA has been trying to persuade it to sign since October, insisting it wants to keep the uranium on its own soil for a simultaneous swap with reactor fuel.

Enriched uranium is the focus of Western suspicions over Tehran's atomic programme, because in a highly purified form it can be used to make the fissile material of a nuclear bomb.

Under the new agreement, a copy of which was obtained by AFP, Tehran is ready to deposit more than half of its LEU in Turkey "within one month."

In return, the United States, France and Russia would deliver 120 kilos of fuel needed for the reactor "in no later than one year."

earlier related report
Sceptical West keeps pressure on Iran after nuclear deal
Paris (AFP) May 17, 2010 - Scepticism greeted Iran's agreement on Monday to ship low enriched uranium to Turkey, with the United States saying it will not halt its quest for tough new sanctions.

"It does not change the steps that we are taking to hold Iran responsible for its obligations, including sanctions," said White House spokesman Robert Gibbs in Washington.

Iran earlier signed an agreement with non-permanent UN Security Council members Turkey and Brazil to ship 1,200 kilograms (2,640 pounds) of its low enriched uranium to Turkey for a later swap for fuel for a research reactor.

Gibbs -- who had earlier Monday issued a written statement expressing "serious concerns" about the deal -- said that if Tehran keeps its word, it would represent "some progress."

But even if that happens, he added, Washington has concerns about the "overall thrust" of Iran's nuclear programme and the fact that Tehran says it would keep enriching uranium to 20 percent.

EU foreign policy chief Catherine Ashton said Monday's deal failed to address the core issue, "which is the nuclear weapon intention issue".

Ashton, talking to reporters in Madrid where she was attending an EU-Latin America summit, said she would wait to see if Iran makes a move to resume talks with the West about its nuclear programme.

"If they do, we will discuss it, if not we will continue what we are doing," she said.

In Paris, French foreign ministry spokesman Bernard Valero said: "Let's not be duped by this. A solution for the medical reactor, while necessary, would in no way resolve the problem posed by the Iranian nuclear programme."

"The exchange of uranium that is envisaged amounts to a confidence gesture, a side issue," Valero told reporters.

His boss, Foreign Minister Bernard Kouchner, said the International Atomic Energy Agency (IAEA) must be the first body to respond to Monday's deal -- a position shared by Germany.

"It of course remains important that Iran and the IAEA reach an accord," its deputy government spokesman Christoph Steegmans said. "That cannot be replaced by an accord with other countries."

The IAEA said it had received the text of the joint declaration by Iran, Brazil and Turkey, but was now expecting Tehran to notify it directly of what commitments it had undertaken.

"In line with what was stated there, we are now expecting written notification from Iran that it agrees with the relevant provisions included in the declaration," said spokeswoman Gill Tudor.

In London, British junior foreign minister Alistair Burt said: "Iran's actions remain a serious cause for concern, in particular its refusal to meet for discussions of its nuclear programme, or cooperate fully with the IAEA."

Western diplomats close to the Vienna-based IAEA said the deal did not remove the case for further UN sanctions against Tehran.

"They're not in trouble over the Tehran Research Reactor deal," said one diplomat, speaking on condition of anonymity.

"So fixing the refuelling for that reactor is not going to put them straight in the eyes of the international community."

Russia, which has been reluctant to pursue new sanctions against Iran, was more optimistic.

"What was done by our colleagues needs to be welcomed. This is the politics of a diplomatic solution to the Iran problem," President Dmitry Medvedev told reporters during a visit to Kiev.

"We need to have consultations with all the parties, including Iran and then determine what to do next."

For the Israelis, who consider Iran's nuclear drive to be a major threat to their security, Tehran had succeeded in having "manipulated Turkey and Brazil," a senior Israeli official told AFP on condition of anonymity.

"The Iranians have already pulled off such a trick in the past -- by pretending to accept such a procedure to lower tensions and reduce the risk of harsher international sanctions, then refusing to follow through," he said.

But Brazil's President Luiz Inacio Lula da Silva called the deal a "victory for diplomacy."

"Israel has the right to say what it wants, but it is the first time that Iran has agreed to send its nuclear fuel to a third country," an adviser to the Brazilian president added.

earlier related report
Nuclear sanctions threat stays for Iran: diplomats
Vienna (AFP) May 17, 2010 - By agreeing to ship some uranium to Turkey, Iran has not removed the case for further UN nuclear sanctions, western diplomats close to the UN atomic watchdog said Monday.

"They're not in trouble over the TRR (Tehran Research Reactor) deal. So fixing the refuelling for that reactor is not going to put them straight in the eyes of the international community," one western diplomat said, speaking on condition of anonymity.

Iran is already under three sets of UN sanctions for refusing to halt its uranium enrichment, which the West fears hides a covert nuclear weapons programme. Tehran insists it will go ahead with enrichment, even after signing the fuel deal.

"It was Iran in the first place who approached the IAEA (International Atomic Energy Agency) because they needed the fuel," another diplomat said.

"They need that fuel, but they've held out on a deal for eight months now. They're not under sanctions over the TRR. They're under sanctions for refusing to halt uranium enrichment, people shouldn't forget that."

Iran announced that it had signed an agreement with Brazil and Turkey, whereby it would ship 1,200 kilogrammes (2,640 pounds) of low-enriched uranium to Turkey in return for fuel for a reactor in Tehran that makes radioisotopes for cancer treatment.

The deal appeared to mark a breakthrough in long-stalled discussions over the refuelling of the research reactor.

The IAEA has been trying to persuade Iran since October to sign a deal with the United States, France and Russia that would see Iran's stockpile of low enriched uranium shipped out of the country and then turned into fuel for the research reactor.

But Iran has so far stalled on the deal, insisting it wants to keep the uranium on its own soil for a simultaneous swap with reactor fuel.

Uranium enrichment is at the centre of western suspicions over Tehran's atomic programme, because in a highly purified form, it can be used to make the fissile material of a nuclear bomb.

Under the new agreement, signed by Iran, Turkey and Brazil and a copy of which was obtained by AFP, Tehran is ready to deposit 1,200kg of low enriched uranium "within one month".

In return, the United States, France and Russia would deliver 120kg of fuel required for the reactor "in no later than one year".

The IAEA made no immediate comment to make on the deal, neither did the US, French and Russian missions to the agency.

Turkish Foreign Minister Ahmed Davutoglu said there was "no need" for further UN sanctions against Iran in the light of the deal.

"This agreement should be regarded positively and there is no need for sanctions now that we (Turkey and Brazil) have made guarantees and the low enriched uranium will remain in Turkey," he said.

"This agreement sends the international community a message that there is always room for diplomacy. Turkey and Brazil showed that it was time for diplomacy," he said.