The United States said today after inconclusive international talks with Iran's nuclear envoy that Tehran must choose between co-operation or confrontation and give up sensitive nuclear work.
"We hope the Iranian people understand that their leaders need to make a choice between cooperation, which would bring benefits to all, and confrontation, which can only lead to further isolation," said State Department spokesman Sean McCormack after the Geneva talks attended for the first time by senior US diplomat William Burns.
He said Mr Burns did not meet separately with any member of the Iranian delegation and that EU foreign policy chief Javier Solana told Iran it must give a "clear answer" to an offer made by world powers within two weeks.
Iran's chief negotiator today ruled out discussion of a major powers demand to suspend uranium enrichment as a precondition to end a long-running dispute over Tehran's nuclear programme.
Speaking after a day of talks with diplomats from six countries, including the United States, Saeed Jalili said that in any next round of talks Iran was not ready to discuss a freeze in enrichment proposed by the "sextet" in return for the UN Security Council halting further sanctions measures.
"We will only discuss common points of the package," Jalili told Reuters.
European Union foreign policy chief Javier Solana said after meeting Mr Jalili that Iran gave no clear answer to the offer, but that he hoped for a fuller response in two weeks' time.
But a senior Iranian diplomat at the Geneva talks said: "Of course we will not discuss freeze-for-freeze topic in the next meeting with Solana. First we would like to discuss the common points and if an agreement is reached then we can discuss our differences."
"The freeze-for-freeze issue cannot be accepted because this (enrichment) is our right and we will never abandon our nuclear right," he added.
"We have not got a clear answer...we didn't get an answer Yes or No and we hope that it will be given soon," Mr Solana told a news conference.
But a Western diplomat at the talks said no further high-level meetings had been scheduled. "This is the last meeting at this level," the diplomat said.
The high-level US participation in the one-day meeting in Geneva, together with Iranian comments playing down the likelihood of an attack by the United States and Israel, had raised hopes of progress and helped ease record oil prices.
But the optimism was tempered by US insistence that despite the presence of its envoy Mr Burns, real negotiations cannot begin until Iran has frozen sensitive nuclear work, a step Tehran has repeatedly rejected.
Iran's ambassador to Switzerland said Iran would not accept a freeze. "As our supreme leader (Ayatollah Ali Khamenei) clearly said, our path is very clear: We are not going to abandon our rights."
Mr Khamenei said on Wednesday Iran was ready to negotiate, but showed no sign of backing down on the Islamic Republic's refusal to halt atomic activities.
Iran, the world's fourth-largest oil producer, rejects suspicions that it wants to build an atom bomb, saying the aim of the nuclear programme is to generate electricity so that it can export more oil and gas.
The UN has imposed three sets of sanctions on Iran in a stand-off that goes back to the revelation in 2002 by an exiled opposition group of the existence of a uranium enrichment facility and heavy water plant in the country.
Tension has intensified since Tehran tested missiles last week, alarming Israel and unsettling energy markets on fears that conflict could disrupt supply.
Yet oil prices slipped yesterday, ending 13 per cent down from last week's record of over $147 a barrel of crude.