A confidential U.N. nuclear agency report found "no evidence" that Iran tried to make atomic arms, but it criticized Tehran (search) for cover-ups and warned it's still uncertain if Iran's nuclear efforts were for peaceful purposes, diplomats told The Associated Press on Monday.

The report also found that Iran had produced small amounts of enriched uranium and plutonium, according to the Washington Post.

In Moscow, a top Iranian official said his country is temporarily halting its uranium enrichment program and has agreed to tougher U.N. inspections.

Citing the report by the head of the Vienna-based International Atomic Energy Agency (search), the diplomats said the 29-page document faults Iran for not telling the truth in the past about its nuclear programs.

Prepared for a Nov. 20 meeting of the IAEA board of governors, the report comes as the United States continues to focus attention on Iran's nuclear activities. The Bush administration has argued that Iran should be declared in violation of the Nuclear Nonproliferation Treaty at that meeting -- a move that would lead to U.N. Security Council (searchinvolvement and possible sanctions.

The diplomats told the AP that the IAEA report also credited Iran for a change of heart since September, when the agency demanded it clear up suspicions it was running a covert weapons program by explaining contradictions and ambiguities in its nuclear activities.

"To date, there is no evidence that the previously undeclared nuclear material and activities ... were related to a nuclear weapons program," said one of the diplomats, reading from the report drawn up by IAEA Director General Mohamed ElBaradei (search). "However, given Iran's previous pattern of concealment, it will take some time before the agency is able to conclude that Iran's nuclear program is exclusively for peaceful purposes."

U.S. officials will likely seize on a passage in the report saying that Tehran's recent disclosures "clearly show that in the past, Iran had concealed many aspects of its nuclear activities, which resulted in breaches of its obligations of the safeguard agreement."

The safeguards, which are meant to ensure all nuclear activities are peaceful, are a key part of the Nonproliferation Treaty.

In its Tuesday editions, the Washington Post said the report found that Iran manufactured small amounts of enriched uranium and plutonium as part of a nuclear program that operated in secret.

"Iran has now acknowledged that it has been developing, for 18 years, a uranium centrifuge program, and, for 12 years, a laser enrichment program," the Post said, quoting the report.

Under international pressure, Iran recently gave the agency what it said was a complete declaration of its nuclear activities just days ahead of an Oct. 31 deadline. On Monday, it also handed over two letters pledging to sign an additional agreement throwing open its program to inspection on demand by agency experts and announcing it had suspended uranium enrichment.

The concessions were announced in Moscow by Hasan Rowhani, the head of Iran's powerful Supreme National Security Council.

"Atomic weapons are not important to our defense doctrine," Rowhani said before meeting Russian President Vladimir Putin, whose government helped build Tehran's nuclear program.

Washington has urged Moscow to freeze its $800 million deal to help build Iran's first nuclear reactor, saying the facility in Bushehr on the shore of the Persian Gulf could help Iran develop weapons. The Kremlin has said it shares some of the U.S. concerns and has prodded Tehran to accept tighter IAEA controls.

Tehran promised weeks ago to suspend its enrichment activities, a key concern.

Iran has acknowledged that it enriched uranium covertly at a sophisticated facility at Natanz, about 300 miles south of Tehran. But it maintains enrichment was only to non-weapons levels, as part of nuclear programs meant to generate electricity.

While acknowledging IAEA finds of traces of highly enriched, weapons-grade uranium on its enrichment centrifuges, it says the "contamination" originated outside Iran and was inadvertently imported with the equipment bought abroad.

U.S. intelligence reports focus on the Natanz enrichment programs in arguing that Iran has been pursuing a clandestine nuclear weapons program.

Diplomats said the United States and its allies would seize on any ambiguity in ElBaradei's report concerning enrichment and other suspicious activities in making a case against Iran. They said the ElBaradei report did not make a judgment on the source of the highly enriched uranium, saying more investigation was needed.

In New York, Secretary of State Colin Powell said the Iranian government is feeling pressure from its people to adopt democratic reforms.

"The Iranian people want their freedom back," Powell said in New York. "They do not want to banish Islam from their lives ... They want to be free of those who have dragged the sacred garments of Islam into the political gutter."

The report credited Iran with "active cooperation and openness," after the last board meeting demanded it unveil previous secrets and cooperate with agency inspectors, the diplomats said.

Before that, however, Iran "failed in a number of instances over an extended period of time to meet its obligations" on honoring its safeguards agreements, of the diplomats said, citing the report. "Iran's policy of concealment continued until last month, with cooperation being limited and reactive and information being slow in coming."

By making his announcement in Moscow, Rowhani bolstered the prestige of the Kremlin, which had taken a position between Washington and Tehran in the dispute.

Putin said "we are pleased to note that Iran has itself resolved to limit itself" on uranium enrichment, and he suggested it cleared the way for further Russian-Iranian nuclear cooperation.

In a separate meeting with Rowhani, Foreign Minister Igor Ivanov said Iran's pledges "will open up additional possibilities for Russian and Iranian cooperation in many spheres, including nuclear."

Rowhani added that Iran already had a project in mind. "In the nearest future, we will carry out discussions with Russia about building a second reactor at the Bushehr power plant," he said, after talks with Ivanov.