Russia, the United States and the European Union stepped up attempts on Thursday to end months of deadlock over Iran's nuclear programme. The powers sought to draft a proposal aimed at satisfying the world that Iran's nuclear intentions are peaceful, but diplomats doubted that Tehran would accept it.
France, Britain and Germany and the United States support the idea of a proposal that would let Iran keep part of its nuclear fuel production programme if the most sensitive part - enrichment - was scrapped and moved to Russia, diplomats say.
UN nuclear watchdog chief Mohamed ElBaradei said he hoped a deal would be reached soon.
"He hopes that in the coming days the international community will be able to coalesce around a solution that is acceptable to all parties, including Iran," the International Atomic Energy Agency (IAEA) said in a statement.
But diplomats were sceptical that Iran would join the proposed Russian joint venture, as that would require Tehran to renounce enrichment, which it says it will never do.
Enrichment purifies uranium for use as fuel in power stations or, if it is enriched further, for use in bombs.
"What ElBaradei said may be wishful thinking," an EU3 official told Reuters on condition of anonymity. "Perhaps the Iranians will make a deal with us, but I think we will be surprised if that happens." Washington accuses Iran of trying to build nuclear weapons under cover of its atomic power programme, which Tehran denies.
Under the plan, Iran could continue with uranium conversion, the step before enrichment, something the West had previously wanted Iran to renounce as well.
Talks between the EU3 and Iran collapsed in August after Iran resumed conversion activities.
Senior EU3 officials met Russian and Chinese envoys in Vienna on Thursday, an EU3 official said, adding that they would meet ElBaradei and speak to senior US officials by telephone.