By Parisa Hafezi and Louis Charbonneau
TEHRAN/VIENNA - Iran has pledged to suspend its uranium enrichment programme to ease concerns that its nuclear programme is aimed at developing weapons, but has warned that the freeze is only temporary.
Hassan Rohani, Iran's chief nuclear negotiator, said on Sunday the suspension would remain in place as long as talks with the EU continued on a final resolution of the issue.
"One hour ago we submitted a letter to the IAEA," Rohani told reporters after a meeting in Tehran with the ambassadors of Britain, Germany and France, which have been negotiating with Iran for several weeks on behalf of the European Union.
Receipt of the letter by the International Atomic Energy Agency, the United Nations' nuclear watchdog, makes the scope and starting date of the suspension legally binding.
Iran's U.N. ambassador, Pirooz Hosseini, declined to say when the freeze would take effect. "Tomorrow we will learn everything," he told Reuters.
A senior EU diplomat close to the talks said Iran had agreed to all points covered in a preliminary agreement hammered out in Paris a week ago. "We have reached a full agreement regarding all the issues mentioned in the package," he said.
Iran, which denies U.S. accusations that it is secretly developing atomic weapons, had held up a final deal by demanding that it be permitted to continue the early stages of uranium conversion. The EU rejected this idea.
"The suspension is what the Europeans wanted, a full one," a diplomat close to the IAEA said.
A diplomat close to the IAEA said the arrival of the letter on Sunday meant it would be included in a crucial report, due to be released on Monday, summarising the IAEA's two-year investigation of Tehran's nuclear programme.
Once confirmed by IAEA inspectors on the ground, the freeze is likely to protect Iran from being reported to the U.N. Security Council for possible economic sanctions when the IAEA board of governors meets on November 25.
The "EU Three" have said that, once the suspension begins, they will discuss a package of incentives with Iran -- ranging from cooperation on peaceful nuclear technology to a possible trade deal -- in return for Iran permanently giving up any activities that could be used to make bomb-grade material.
Rohani's deputy Hossein Mousavian told reporters those talks would start on December 15.
However, questions remain, as Iran has continued to insist that it will never give up its "sovereign right" to enrich uranium, even while negotiating with the EU.
"We have accepted the suspension as a voluntary step and it does not create any obligations for us," Rohani's deputy, Hossein Mousavian, told Iranian state television.
Washington, which accuses Iran of using its nuclear power programme as a front to develop nuclear weapons, wants the IAEA to refer the case upwards because Tehran concealed a uranium enrichment programme for 18 years.
Diplomats in Vienna said that, with a suspension in place, the United States would have only a handful of supporters on the IAEA's 35-member board for such a move.
The White House reacted cautiously to Iran's announcement, saying: "We look forward to a briefing by our European friends".
The IAEA board had demanded in September that Iran freeze its enrichment programme. But Tehran has continued producing parts for centrifuges that purify uranium for use in nuclear power plants or weapons.