The US will confront Iran with accusations it is developing nuclear weapons in crunch talks next month between Tehran and six world powers which are set to be held in Turkey, officials said on Tuesday.
The announcement that long-awaited talks will take place from October 1 was greeted as a welcome first step by United States officials but a White House spokesman made clear there will be no holds barred in the discussions.
The European Union's foreign policy chief Javier Solana meanwhile said the talks would "very likely" take place in Turkey, a country seen as having good relations with both the West and the government in Tehran.
Tehran has consistenly denied its uranium enrichment activities are part of an attempt to manufacture weapons and are merely for energy needs. It has said it would be prepared to field questions about the atomic programme but will not trade away its rights to nuclear energy.
"I don't know what's on their agenda, but I know what's on our agenda and I know what's on the agenda for countries around the world that are concerned about Iran's illicit nuclear weapons program," White House spokesman Robert Gibbs told reporters on Monday.
"It will be part of that discussion, and if Iran is unwilling to discuss their illicit nuclear weapons programme, I think all that does is strengthen the hand of the international community in underscoring the obligations, again, that the Iranians are failing to live up to.
"So I think this will be an interesting moment and we'll see if it's something that -- if it's something they don't want to talk about, I think that will speak volumes around the world."
The agreement for the talks to begin at the start of next month was sealed on Monday in a phone call between Solana and Iran's top nuclear negotiator Saeed Jalili, days after Tehran submitted new proposals.
Six countries -- Britain, China, France, Germany, Russia and the United States -- will take part in the talks with the Iranian delegation.
Tehran is already under three sets of UN sanctions and European diplomats said last week that the EU could consider introducing more unilateral sanctions if the UN Security Council cannot agree to do so.
Speaking Tuesday ahead of a meeting of European Union foreign ministers, Solana said dialogue was still regarded as the best forward but also stressed a "double-track approach" -- the carrot and stick of trade, aid and sanctions.
"At this point in time, we are going to try to enter into a negotiation," said Solana.
The talks will involve the political directors of the foreign ministries of the six powers, including the State Department's William Burns.
The seven-way meeting is the first since July last year, when then-president George W. Bush sent Burns to an inconclusive one-off meeting with Iran in Geneva.
Solana said he expected the US involvement to be deeper this time.
"The Americans will be present in a formalised manner -- this is new and I think that has to be evaluated positively by the Iranians," he told reporters.
While Bush's successor Barack Obama has initiated a more open policy towards Tehran, Washington had expressed disappointment with the new package of proposals, saying it did not address its greatest concern on nuclear weapons.
The head of Iran's Atomic Energy Organisation, Ali Akbar Salehi, said Monday that Tehran was ready to field questions about its atomic programme, but will not horse trade on its fundamental rights to nuclear energy.
"As our president has said, there is no room to bargain on (our) sovereign right (to nuclear energy technology). But once it comes to discussion, everyone is free to pose any question they wish," he told reporters in Vienna.