VIENNA (Reuters) - Iran agreed to answer remaining questions about its past covert nuclear activities within a month during talks with International Atomic Energy Agency chief Mohamed ElBaradei, the U.N. watchdog said on Sunday.
Tehran also provided information about work to develop advanced centrifuges, it said. The IAEA has long sought such data to assess how close Iran is to mastering uranium enrichment technology that could be used to produce fuel for atom bombs.
Skeptical Western diplomats said there was no sign Iran had budged from its refusal to suspend enrichment or end curbs on IAEA inspections, steps they say would do more to defuse a standoff over the Islamic Republic's nuclear activity.
ElBaradei met Iranian leaders over two days last week to push for swifter cooperation to wrap up a long-running IAEA inquiry into the past and shed light on Iran's current program, which the West suspects is meant to yield warheads.
Iran says it wants to refine uranium only for electricity.
ElBaradei is anxious to see a standoff between Iran and Western powers over its nuclear ambitions settled peacefully, a concern underscored by a U.S.-Iranian naval incident in the Gulf a week ago which has fanned tensions.
After years of stonewalling that helped lead to U.N. sanctions, Iran agreed in August to clarify questions about its nuclear past, a process called the "work plan", within months.
An end-of-year target passed with issues still open. But the IAEA said the Tehran talks yielded an Iranian commitment to settle all issues in time for ElBaradei's next Iran report to a meeting of the agency's 35-nation board in early March.
"Agreement was reached on the timeline for implementation of all remaining verification issues specified in the work plan. According to the agreed schedule, implementation ... should be completed in the next four weeks," the IAEA statement said.
A diplomat close to the IAEA said ahead of ElBaradei's visit that the agency inquiry had entered a final phase with Iran addressing U.S. intelligence given to U.N. inspectors about past attempts to "weaponize" atomic material.
The diplomat said on Sunday the Tehran talks result was "positive, constructive and substantive" enough for the IAEA to reverse plans not to issue a statement afterwards.
Mohammed Saeedi, deputy head of Iran's atomic energy agency, said the new timeline was agreed on Iranian initiative and would show the world Tehran's nuclear goals were peaceful all along.
"Iran has nothing to hide and therefore has no fear to answer remaining questions ... to pave the ground for (the IAEA) to give a transparent report about Iran's program," he told the official news agency IRNA.
Western diplomats had feared Iran would lose motivation to complete the "work plan" after a threat of tougher U.N. sanctions faded following a U.S. intelligence report saying Tehran had stopped an active nuclear weapons program in 2003.
The report also said Iran was still striving to develop enrichment abilities that could be militarized later but many analysts said it weakened political restraints on the program.
Western diplomats reserved judgment on ElBaradei's talks. Some said Iran did not need another month to come clean because it has known what information the IAEA needed for a long time.
White House spokesman Gordon Johndroe said Iran must still suspend its enrichment activity. "Another declaration is no substitute for complying with the U.N. sanctions," he said.
ElBaradei also tried to impress on Iran the need to permit wider inspections and show that it is enriching uranium only as an alternative to its oil and gas reserves.
To that end, the statement said: "Iran also provided information on its research and development activities on a new generation of centrifuges." They are being developed at workshops which Iran has kept off limits to U.N. inspectors.
Additional reporting by Parisa Hafezi in Tehran