TEHRAN, Iran – Iran told the U.N. nuclear watchdog agency yesterday it plans to resume nuclear fuel research after a 2 1/2 -year hiatus, a vague declaration that was likely to be taken in the West as fresh evidence Tehran is trying to build an atomic weapon.

The International Atomic Energy Agency’s head, Mohamed Elbaradei, said it was important that Tehran “maintains its suspension of all enrichment-related activity” as a way of reducing international suspicions about its nuclear plans.

The deputy head of the Atomic Energy Organization of Iran, Mohammad Saeedi, said research would “resume in cooperation and coordination with the IAEA in the next few days, “adding that it would “have little to do with the production of nuclear fuel.”

Beyond that, he would not specify what type of research Tehran planned but claimed its nuclear program had suffered significantly during the research suspension. He said Iran could no longer keep its research scientists in limbo.

Iran has said it remains determined, at some point, to resume uranium enrichment, a process that can produce fuel for nuclear weapons.

Yesterday’s announcement, while vague, was certain to raise further concerns in America and among its European allies who believe Iran wants to build a nuclear arsenal. Tehran says its nuclear program is for electricity generation.

Mr. ElBaradei also called on Iran to “build confidence and enable the resumption of dialogue with all concerned parties.”

The Iranian mission to the IAEA said Tehran has decided to resume from February 9 research and development “on the peaceful nuclear energy program which has been suspended,” Mr. ElBaradei told the agency’s board.

A European diplomat accredited to the agency said it was too early to evaluate the significance of the move and whether it would scuttle talks planned for later this month.

The European Union has previously said any decision by Iran to resume work on its uranium enrichment program would be “the red line” that would end European attempts to negotiate differences with Iran.

Furthermore, the E.U. has said a resumption of work on the program would revive attempts to take Iran to the U.N. Security Council for violating the nuclear nonproliferation treaty.

But the diplomat, who demanded anonymity because he was not authorized to publicly discuss E.U. strategy, said the Europeans needed details of precisely what Iran planned to research before making a decision on future talks.

Iran has come under heavy international pressure from the IAEA and the West to abandon its program to produce fuel for its Russian-built nuclear reactor, due to come online this year and for its future nuclear power plants.

Iran has vowed it will never give up the right to produce nuclear fuel, which it says is guaranteed by the nuclear nonproliferation treaty.

While refusing to renounce permanently uranium enrichment, Iran suspended many aspects of its nuclear fuel program in 2003 as a goodwill gesture during negotiations with the big three European powers, Britain, France, and Germany.

The talks collapsed in August after Iran resumed uranium reprocessing activities, a step before enrichment, at its Uranium Conversion Facility in Isfahan, central Iran.

While the two sides resumed dialogue last month, talks have so far failed to resolve the dispute. More talks are scheduled for later this month.