The pause could represent an attempt to de-escalate Iran's conflict with the Security Council, which is deliberating a new set of harsher sanctions on the Islamic Republic.

Iran has enriched small quantities of uranium to the low level suitable for nuclear fuel generation. The U.S. and its allies fear that Iran could build nuclear weapons with larger amounts of more highly enriched uranium.

Hard-line President Mahmoud Ahmadinejad had been expected to announce last month that Iran had started installing 3,000 uranium-enriching centrifuges at a facility in the desert outside the central city of Natanz, where it has about 500 centrifuges above and below ground. But the announcement never materialized, an apparent step back that IAEA chief Mohamed ElBaradei appeared to confirm Monday.

"I do not believe that the number of centrifuges has increased, nor do I believe that (new) nuclear material has been introduced to the centrifuges at Natanz," he said.

ElBaradei, whose agency has spent more than four years probing Tehran's nuclear activities, warned that, despite the new bit of positive news, lack of Iranian cooperation left the IAEA unable to establish that Tehran's nuclear activities were purely peaceful.

Unless Tehran takes "the long overdue decision" to cooperate with the IAEA, it "will have no option but to reserve its judgment about Iran's nuclear program," he told reporters.

And a senior Iranian official dashed hopes that any short-term pause could translate into Tehran accepting a U.N. Security Council demand to freeze its enrichment activities. Ali Ashgar Soltanieh, Iran's chief IAEA delegate, said his country would "never give up its inalienable right" to enrich uranium, a refrain repeated almost daily by Iranian representatives in the standoff.

Diplomats familiar with the agency's Iran file said Tehran continues to refuse IAEA requests to install cameras that would give agency monitors a full view of its underground hall at Natanz, which Iran says will ultimately house 54,000 enriching centrifuges - enough to produce dozens of nuclear weapons a year.

Iran has produced and stored 250 tons of the gas used as the feedstock for enrichment. That would be enough to produce more than 40 nuclear bombs.

Lack of full remote monitoring means the agency cannot keep tabs on all activities at the bunker, said one diplomat, who demanded anonymity because he was not allowed to discuss the issue. Iran continues to assemble individual centrifuges without connecting them into the cascade needed to enrich uranium in the hall, he said.

Up for review as early as Tuesday will be a Feb. 22 report from ElBaradei finding that Tehran has set up hundreds of centrifuges.

The board was expected to approve last month's decision by ElBaradei to suspend nearly half the technical aid his agency provides to Iran. Only North Korea and Saddam Hussein's Iraq have faced such punishment in the past.

The United States, its key allies and most European nations have in the past been opposed by nonaligned board members who were against harsh punishment.

But the diplomats said that even nations normally backing Tehran - including key U.S. critics such as Cuba and Venezuela - would likely agree to the suspensions because they were backed by the U.N. Security Council.

The European Union, in a statement made available in advance to The Associated Press, said it backed the suspensions, saying it "supports the (IAEA) ... views" on the 18 projects that could be suspended.

The board will also be reviewing North Korea's apparent willingness to ultimately dismantle its nuclear arms-making capabilities.

ElBaradei plans to go to Pyongyang on March 13 as part of the six-nation agreement under which North Korea agreed to allow a return of his agency's experts after more than four years under its commitment to eventually scrap its nuclear program in exchange for economic aid and security assurances.