TEHR AN (AFP/Reuters) - Iran on Wednesday rejected plans for it to send most of its stocks of low-enriched uranium abroad, delivering a severe blow to UN-brokered efforts to allay Western concerns over its nuclear ambitions. The decision is expected to anger the US and its allies, which had called on Iran to accept a deal which aimed to delay Tehrans potential ability to make bombs by at least a year by divesting Iran of most of its enriched uranium. Iranian Foreign Minister Manouchehr Mottaki said Iran has ruled out proposals backed by the major powers for it to ship out more than 70 per cent of its stocks before receiving any nuclear fuel in return, the ISNA news agency reported. France, which had been set to play a central role in the proposed deal, swiftly expressed disappointment with the Iranian position. There is a clear and negative response from the Iranians, Foreign Minister Bernard Kouchner said, adding that France will nevertheless continue to speak with Iran. Mottaki said Iran is prepared to consider the idea of a simultaneous exchange of uranium for fuel but the UN nuclear watchdog, which has been brokering the negotiations, has already said that idea is unacceptable to the Western powers. We will definitely not send out our 3.5pc enriched uranium, Mottaki said. He said Tehran is ready to consider swapping the fuel simultaneously in Iran and is prepared to enter new talks with the major powers. Mottaki criticised Washington for pressuring Iran to accept the deal. Diplomacy is not black or white. Pressuring Iran to accept what they want is a non-diplomatic approach, he said. He said Iran is still considering how much of its stocks of low-enriched uranium it should ship out in any deal. Under the IAEA-brokered proposals, Iran would send out 1,200 kilograms, which would then be further enriched by Russia and converted into fuel by France before being supplied to the Tehran reactor. The amount they mentioned for the swap is not acceptable ... and our experts are still studying it, the Iranian Foreign Minister said. US leaders have expressed mounting pessimism about the prospects of an agreement. Western governments support the UN-brokered deal because they believe it would leave Iran with insufficient stocks of low-enriched uranium with which to make a bomb. Irans envoy to the UN nuclear watchdog Ali Asghar Soltanieh said the main problem is a lack of trust between Tehran and Washington after three decades of diplomatic rupture. We have this confidence deficit. Therefore we have to be 100pc sure that there is a guarantee, Soltanieh told reporters in Vienna. Asked about Mottakis remarks, he said Tehran wanted a guarantee that it would receive fuel it contracted for. We want to be sure that there is a guarantee that we will receive the fuel at the end of the day for the Tehran research reactor. He recalled that Tehran once paid the United States and France to provide nuclear fuel but it was never delivered because of the 1979 Islamic Revolution. We never got the fuel or our money back. So a guarantee is now the pivotal issue for us. More than 200 hospitals in Iran depend on this reactor, Soltanieh told reporters after an informal meeting of IAEA governors in Vienna. We are ready for a second round of negotiations to finalize this matter. But we want a 100 percent guarantee.