The US clashed with Brazil and Turkey over the next steps on Iran, with US officials saying a proposed atomic fuel deal for Tehran must not derail the UN drive to impose new sanctions over Iran's nuclear program.

In signs of the deep rift between the US and two influential nonpermanent members of the UN Security Council, Turkey and Brazil stepped up to defend their proposal as the right thing to do to reduce tensions over the Iranian nuclear impasse.

'We know we did the right thing,' Brazilian Foreign Minister Celso Amorim told a news conference, flanked by Turkish Foreign Minister Ahmet Davutoglu.

'We are seeking to follow a path of dialogue, a path of conversation and understanding, and that has produced results.'

Brazilian President Luiz Inacio Lula da Silva and Turkish Prime Minister Recep Tayyip Erdogan traveled to Tehran earlier this month to broker the deal under which Iran agreed to send 1,200 kg of its low-enriched uranium abroad in exchange for specially processed fuel for its medical isotope reactor.

Senior US officials dismissed the fuel deal proposal, saying Turkey and Brazil appeared to have been hoodwinked by Tehran in its efforts to escape new UN sanctions.

'We very much recognize the sincere efforts that were made by Brazil and Turkey ... but unfortunately I think the motives of the parties were quite different,' said one senior US official, speaking on condition of anonymity.

'I think Iran's main interest was to have a proposal in play that would reduce momentum toward a sanctions resolution.'

Iran rejects Western allegations its nuclear program is aimed at developing weapons. It says its atomic ambitions are limited to the peaceful generation of electricity and refuses to suspend uranium enrichment.

Iran's foreign minister said on Friday he believed Western powers were considering the fuel deal, which he said could foster cooperation instead of confrontation over Iran's nuclear plans.

Moving on sanctions

The deal brokered by Brazil and Turkey resurrected elements of a compromise floated in October by the International Atomic Energy Agency.

The IAEA proposal was seen as a confidence-building measure to allow more time to work with Tehran. But Iran walked away from the table, setting in motion US-led moves to build consensus around new UN sanctions.

The United States and the other permanent Security Council members -- Britain, China, France and Russia -- along with Germany agreed on the framework for such a resolution this month and plan to move ahead in submitting it to the full council as soon as possible, the US officials said.

'In our view the joint declaration falls short of what's necessary. But regardless of this ... proposal, it is important that we proceed to New York to adopt the resolution.”

The officials said the fuel swap proposal did nothing to address the core issues of Iran's continued enrichment of uranium or its revelation of a secret centrifuge facility at Qom, to which the IAEA has still not been given full access.

They also said Iran had moved forward both with enrichment plans and with building its nuclear stockpile since the original proposal was proposed -- making the fuel swap idea pointless.

'Now Iran has roughly doubled the amount of its low enriched uranium. Even if you send 1,200 kilos out, there's more than enough remaining to produce a nuclear bomb,' the official said. 'Time has overtaken the original proposal and this has not been corrected.'

State Department spokesman P.J. Crowley said Secretary of State Hillary Clinton, who has led the US drive for tough new measures against Iran, would likely meet Turkish Foreign Minister Ahmet Davutoglu in Washington on Tuesday to compare notes on Iran.

Davutoglu, speaking in Brazil on Friday, said Turkey and Brazil were following in the footsteps of US President Barack Obama, whose 2008 campaign platform called for greater engagement of the Islamic Republic.

'This (agreement) is a success for Turkey and Brazil, but it is also a success for President (Barack) Obama's policy of engagement,' Davutoglu said. – Reuters