Russia has backed away from what EU diplomats said was a proposal to let Iran do some atomic research if it agreed to refrain from enriching uranium on an industrial scale for 7-9 years.
Russia abandoned the informal proposal, aimed at finding a compromise to the crisis over Iran's nuclear programme, after Western rejection of the idea.
The United States and the European Union want Iran to shelve all work to enrich uranium because of suspicions that Tehran is secretly trying to make nuclear weapons.
Meanwhile, US Vice President Dick Cheney said that Iran would be stopped from getting atomic bombs and faced "meaningful consequences" if it persists in defying calls to stop nuclear work which could lead to weapons.
In defying calls to halt all enrichment-related work, Iran seems to be counting on divisions in the UN Security Council over whether to resort to sanctions mooted by the United States.
Russian Foreign Minister Sergei Lavrov denied after talks with US Secretary of State Condoleezza Rice that he had made a new proposal to defuse a crisis over Iran's nuclear aspirations that the Security Council may soon tackle.
"There is no compromise new proposal," Lavrov said at a news conference with Rice, who added: "The Russians did not tell us of any new proposal ..."
EU diplomats said Russian officials informally raised the idea of a 7-9 year moratorium during consultations over the past week. US, British, French and German rejection came swiftly when word of the offer leaked today.
"The Russians explored this idea with us," said a diplomat, who asked not to be identified, from one of the three EU states - Germany, France and Britain - working on the Iran issue, the so-called EU3.
The diplomat said when Lavrov "realised the EU3 and US would not accept its elements, he decided to deny it to save face".