World powers gathered in London to try and break a deadlock over how to stop Iran enriching uranium, as Tehran again warned against military intervention.
Iran's nuclear ambitions show no sign of waning despite increased international pressure
Senior officials from the US, Germany, Britain, Russia and China met to discuss a European proposal at closed-door talks to offer Tehran incentives to suspend uranium enrichment work.
Iran's president, however, dampened hopes of any progress by insisting on Iran's right to a full range of nuclear technology, and Britain said it did not expect the meeting to achieve a breakthrough.
The meeting was been called amid an escalating international standoff over an Iranian civilian nuclear power program that the United States claims hides the development of atomic weapons.
The European Union's "big three" -- Britain, France and Germany -- are hoping to coax Iran into suspending uranium enrichment work in exchange for a package of trade and technology incentives.
Cheney, Rice: Differing opinions
However, they want Russia and China to join in sanctions, including an arms embargo, if Iran does not agree, according to a draft proposal. And just ahead of the talks, a report emerged of differences of opinion within the US administration over strategy.
Condoleezza Rice, speaking at a meeting on Iran's nuclear policies, in March
US Secretary of State Condoleezza Rice had "gone out on a limb" to back the European package of trade and technology incentives but had met resistance from Vice-President Dick Cheney, the Financial Times newspaper reported.
Cheney is said to be against the idea of "rewarding bad behavior" after Iran allegedly breached its nuclear safeguards commitments, according to the newspaper report based on comments from diplomats and analysts.
It said that the divisions were complicating the EU proposal that world powers support Iran's building of several light water reactors, set up a nuclear fuel bank, and have the United States drop restrictions on Iran's buying of US commercial airplanes, if Tehran takes steps to guarantee it will not make nuclear weapons.
But if Tehran does not do this, sanctions should follow, including an arms embargo, according to the proposal.
Russia supports EU plan
The newspaper said some European diplomats think the US will back their proposals if Russia supports a tough UN resolution that would require Iran to suspend uranium enrichment.
Russian Foreign Ministesr Lavrov (left) met German Foreign Minister Frank-Walter Steinmeier in April to discuss the Iran issue
During a tour of Arab Gulf countries Kuwait and Qatar on Tuesday, Russian Foreign Minister Sergei Lavrov said Moscow supports the EU proposal and urged Tehran to cooperate.
Asked if Russia would back military action against Iran if the proposed negotiations collapsed, Lavrov declined to answer but insisted that Moscow does not support the use of force "in principle."
The United States, Britain, France, China and Russia are the five permanent members of the UN Security Council, which has the power to endorse sanctions or US military strikes, an option which is nonetheless broadly opposed.
Iran's hardline government has already rejected the European offer and insisted its uranium enrichment program is not up for negotiation. In Tehran earlier, Iranian President Mahmoud Ahmadinejad boasted that the Islamic republic had "mastered the entire nuclear fuel cycle" and that it would give an "historic slap" to any attacker.
UN Secretary-General Annan urged Iran to hear out the latest proposal
U.N. Secretary-General Kofi Annan, speaking in Vietnam, said he had appealed to Iran to reassure the world that its nuclear intentions are peaceful and asked it "not to reject anything out of hand" which might emerge from the talks in London.
Exercise in futility?
But one EU diplomat said it was hard to see what the meeting, which started around midday, could achieve. "It's really just an academic exercise, since the Iranians have made it clear that they won't accept any offer," he told Reuters news service.
The United States has refused to rule out military action.
Iran says it wants to use the fuel cycle only to make civilian reactor fuel, and argues such work for peaceful purposes is a "right" enshrined by the nuclear Non-Proliferation Treaty. But the same technology can be extended to make atomic weapons, and the US in particular claims Iran is merely exploiting a loophole in the NPT.
Citing US officials, Iranian analysts and foreign diplomats, the Washington Post newspaper reported Wednesday that Iran had requested through intermediaries direct talks with Washington over its nuclear program.