Mohamed ElBaradei, head of the UN nuclear watchdog, urged Iran on Monday to clarify its response to a US-backed proposal that would have Teheran ship most of its nuclear material abroad for processing.
Iranian officials sent mixed signals on the proposal that would have Teheran export 70 percent of its enriched uranium - enough to build a bomb - and having it returned as fuel for its research reactor, with the foreign minister saying Monday that option still exists and a senior diplomat suggesting the opposite.
The contrasting messages appear designed to keep the international community off balance on how far Iran is ready to go in accepting the original proposal.
Addressing the UN General Assembly, Mohamed ElBaradei said "a number of questions and allegations relevant to the nature" of Iran's program remained, and he called for confidence building measures on all sides.
"I therefore urge Iran to be as forthcoming as possible in responding soon to my recent proposal, based on the initiative of the US, Russia and France, which aimed to engage in a series of measures that could build confidence and trust," ElBaradei said in his final address before stepping down after 12 years as chief of the International Atomic Energy Agency.
In his address, ElBaradei also dismissed the growing calls for sanctions to dissuade Iran from its nuclear ambitions saying that they "too often hurt the most vulnerable and innocent."
He said the UN Security Council should instead focus on "conflict prevention and address the insecurities that lie behind many cases of proliferation such as mistrust and unresolved conflict."
ElBaradei called for confidence building measures on all sides.
"The issue at stake remains that of mutual guarantees amongst the parties," ElBaradei said, adding "trust and confidence-building are an incremental process that requires focusing on the big picture and a willingness to take risks for peace."
While Iran insists it is interested only in enriching uranium for use in a future network of nuclear reactors, it has amassed more than 1,500 kilograms of low-enriched uranium - more than enough to arm a nuclear warhead.
Iranian Foreign Minister Manouchehr Mottaki, who spoke to reporters in Kuala Lumpur, simply replied "No," when asked if his country had rejected the plan that would commit his country to ship out most of its enriched uranium.
Instead, he said Iran has three options to procure fuel for its reactor; to buy the fuel from other countries; to enrich the uranium domestically, or to accept the UN-brokered plan.
In contrast, Ali Asghar Soltanieh, Iran's chief envoy to the IAEA, said Iran wanted to purchase ready-made uranium from abroad for the research reactor.
"We want to buy the fuel from any supplier," he told The Associated Press, fending off repeated questions on whether this meant the rejection of the export plan.
Soltanieh's comments were the most concrete statement yet by a government official of what the Iranian government wanted.
But the US and its allies are unlikely to accept anything substantially less than the original plan, which aimed to delay Iran's ability of making nuclear weapons by at least a year by divesting Iran of most of its enriched uranium and returning it as research reactor fuel.
"We are waiting for Iran to accept formally the agreement," French Foreign Minister Bernard Kouchner said Monday. "We are waiting for this answer. If this answer is dilatory as it seems to be, we won't accept it."