Updated

Iran has slowed the rate at which it is expanding its controversial uranium enrichment program, according to an International Atomic Energy Agency report.

Iran is still defying U.N. Security Council demands to stop enriching uranium, a process that can produce fuel for atom bombs, and refused to allow IAEA inspectors to check its Arak heavy water reactor project after a dome had been built over it to block satellites from taking images of the facility.

The U.N. nuclear agency also reported Thursday that it has found new traces of processed uranium and graphite in samples taken from a Syrian site being investigated for possible hidden nuclear activities.

The finding is part of a restricted report on Syria being circulated among the IAEA's 35 board member nations.

The Iranian report did not suggest any reason for the enrichment slowdown. But agency chief Mohamed ElBaradei said earlier this week that the reason appeared to be "political" — indicating that Iran may be waiting for conciliatory signals from the new U.S. administration, which has said it is ready to break with past American policy and talk directly with Iran on nuclear and other disputes.

To date, Iran has enriched more than 1,600 pounds of low-enriched uranium suitable for nuclear fuel, the report said. U.N. officials have said that Tehran would have to produce less than twice that to begin enriching it to the weapons-grade level needed to produce a warhead.

Both reports were obtained by The Associated Press ahead of a board meeting starting March 2 that will have the nuclear activities of the two Mideast nations on its agenda.

The two documents painted a generally disheartening picture of the nuclear agency's efforts to probe the Iranian and Syrian nuclear programs.

On Iran, the report "regrettably" noted Tehran's "continued lack of cooperation" in agency efforts to investigate suspicions the Islamic Republic had at least planned to make nuclear weapons. It also said Iran continued both uranium enrichment and building a heavy water reactor that will produce plutonium — like enriched uranium, a possible component of nuclear warheads.

The Syria report noted Syria's refusal to allow agency inspectors to make follow-up visits to sites suspected of harboring a secret nuclear program despite repeated requests from top agency officials.

The brevity of the reports — the one on Iran ran five pages, the one on Syria was just three — reflected the lack of progress in the separate agency probes.

Still, a senior U.N. official who asked to remain anonymous in exchange for commenting on the restricted reports, described as significant the find of new uranium traces from samples taken during a one-off visit in June to the Al Kebab site bombed in 2007 by Israeli jets.

The first minute traces of processed uranium from those samples were found late last year. The official said additional analysis had found 40 more uranium particles, for a total of 80 particles.

Additionally, the official said, experts were analyzing minute traces of graphite and stainless steel found at and near the site, although he cautioned it was too early to say whether they were related to nuclear activity.

Inspectors at the Al-Kibar site were known to be looking for graphite, an element in the type of North Korean prototype that the United States says the Syrians were trying to build with help from Pyongyang.

The Associated Press and Reuters contributed to this report.