Iran offered on Friday to negotiate with six world powers about its disputed nuclear program in a new bid to end growing concern that it could be used to produce weapons.
The move, following a hiatus of more than a year, was anticipated in the wake of an invitation to the Iranian leadership last month by chief EU envoy Catherine Ashton and following repeated statements by Tehran officials that they were ready for talks.
Ashton called the Iranian offer "a very important" development. Still, after eight years of Tehran refusing to halt uranium enrichment, despite U.N. Security Council sanctions, officials from the main countries trying to engage Iran expressed little hope of a breakthrough.
German Foreign Minister Guido Westerwelle said the readiness to talk should be viewed positively, "but out of the signals ... must come really concrete talks."
Tehran has said its uranium enrichment is designed only to generate nuclear power. But it also could be used to manufacture weapons-grade uranium as fissile warhead material.
While Tehran argues that it has a right to enrich for peaceful purposes, international concern is building over Tehran's nuclear secrecy and its refusal to allow the International Atomic Energy Agency to follow up on U.S. and other intelligence detailing alleged Iranian experiments geared at making nuclear arms.
Iran's Supreme National Security Council said in a letter to the EU's foreign policy chief that Iran is ready to hold talks after Nov. 10 "in a place and on a date convenient to both sides," the country's news agency reported.
Ashton had suggested Vienna, but the venue remained undetermined.
According to a U.N. diplomat familiar with the talks, the two sides are exchanging letters now on the date and place of the November meeting.
With expectations modest, Washington appears keen to use the talks to demonstrate unity among the six powers _ the U.S. Russia, China, Britain, France and Germany _ in trying to bring Tehran to a nuclear compromise. Unity has been strained by disagreement over Iran's earlier offer to resume talks that are separate from the six-nation negotiations.
Those talks involving the U.S., Russia, France and Iran stalled last year after Tehran refused an offer to ship out most of its low-enriched uranium and have it turned into fuel rods for its isotope-making research reactor.
Moscow and Paris are ready to resume those talks, but the U.S. has said they have outlived their usefulness in reducing Iran's potential to make nuclear weapons.
The plan was meant to delay that capacity by stripping Iran of most of the enriched uranium, while providing it with the fuel needed to continue making medical isotopes. But Tehran first balked at shipping its enriched uranium, then started enriching uranium to a higher level.
Tehran has said it is enriching uranium to 20 percent to make fuel for its research reactor, but the move alarmed the international community because Iran could get nuclear fuel for the Tehran research reactor from other countries.
The level is also much higher than the 5 percent enrichment needed for a civil nuclear energy program. Uranium enriched to 20 percent can be turned into weapons-grade material enriched to 90 percent much more quickly than low-enriched uranium.
The U.N. diplomat said the six parties are going to work on their "proposals of substance" to put to the Iranians in light of Tehran's enrichment of uranium to 20 percent. The diplomat spoke on condition of anonymity in New York because the discussions are private.
Tehran also has continued to stockpile low-enriched uranium to the point where experts say it has enough for roughly two bombs after higher enrichment, as compared to one when the talks first began about a year ago.
A senior U.S. official told The Associated Press that an offer for new talks on a fuel swap deal could be revived in discussions between the six powers and Iran, but only if Iran agrees to ship out substantially more low-enriched uranium than when the offer was first made over a year ago and to halt its production of higher-enriched uranium.
Considering Iran's staunch stonewalling of the original plan, it is unlikely to agree to do that, the official said on anonymity because his information was confidential. Still, the Russians and the French want to keep discussing such an option and it could promote wider discussions, including international demands that Iran freeze all uranium enrichment, the official said.
If Iran then continues its defiance, there might be enough political will within the six powers to "go for the jugular" he said, suggesting a new round of tougher U.N. sanctions.
Such penalties _ and existing sanctions imposed unilaterally by the EU, the U.S. and other countries _ already show signs of biting, with dozens of major international companies in the banking, energy and industrial sectors curtailing business with Iran over the past year.
This week, the EU published its own sanctions against Iran, which prohibit investing in Iran's oil and gas industries, including the transfer of equipment and technology. Also targeted are shipping, air freight, insurance and banking, and companies and individuals linked to Iran's Revolutionary Guard Corps, which plays a major role in the country's politics and economy.
In addition, EU governments will monitor the activities of Iranian financial institutions on their territory. The EU is Iran's largest trading partner. Germany, Austria and Italy also have significant economic ties with Tehran.
A European Union diplomat said some of the credit for the new Iranian offer should go to China and Turkey, which recently sent officials to Tehran to persuade the leadership to accept the talks offer. China is Iran's closest ally among permanent U.N. Security Council members, and Turkey has stepped up trying to mediate the dispute.
In Friday's message regarding new talks, Iran referred to an earlier letter that included conditions for restarting talks. Sent in July, it asked the six nations to clarify their position on Israel's nuclear program, which is widely believed to have included the production of a sizable nuclear arsenal. Iran failed in a push in September for the U.N. nuclear agency to censure Israel for shielding its nuclear programs from inspection.
Earlier this month, Iranian President Mahmoud Ahmadinejad endorsed the idea of new talks but warned they would fail if the West does not oppose Israel's suspected nuclear arsenal.
Friday's letter, however, did not list those conditions, which also included a demand to know when sanctions would be lifted and when the U.S. would give up its nuclear weapons.
Officials talking to the AP said the upcoming talks would likely include non-nuclear subjects, but the agenda was still being set.
AP writers Nasser Karimi in Tehran, Iran; Matthew Lee in Washington; Geir Moulson in Berlin; David Stringer in London; Mike Corder in Brussels, and Edith M. Lederer at the United Nations, contributed to this report.