In a reversal, Iran has acknowledged importing parts for advanced centrifuges that can be used to enrich uranium, the U.N. atomic watchdog agency said Tuesday in a confidential report obtained by The Associated Press.

The report by the head of the U.N. atomic watchdog agency credited Iran with more nuclear openness but said questions remained about nearly two decades of covert activities first revealed nearly two years ago, the China Daily website said Wednesday.

The dossier was issued for the June 14 meeting of the IAEA's 35-nation board of governors that has wrestled for more than a year about what to do about what that the United States and its allies say is a weapons program.

Uranium enrichment is one way to make nuclear warheads, although the process can also be used to generate power, depending on the degree of enrichment.

In an interview with The Associated Press before the report was leaked, U.S. Undersecretary of State John R. Bolton accused Tehran of engaging in "denial and deception."

"We are convinced that they are pursuing a clandestine program to acquire nuclear weapons," he said.

Bolton, who was at a review conference of the U.S.-launched Proliferation Security Initiative to stop the spread of weapons of mass destruction, said Washington was determined to have it answer to the U.N. Security Council.

While the report did not appear critical enough of Iran to marshal strong support at the board meeting for such a move, it also was far from the clean bill of health Tehran had hoped for in making a case that the books should be closed on its nuclear activities.

Mohamed ElBaradei, the IAEA chief, said earlier Tuesday his agency had not found proof to date of a concrete link between Iran's nuclear activities and its military program, but "it was premature to make a judgment."

Iran has rejected the U.S. allegations, saying its nuclear program is geared only toward generating electricity.

Concerns over Iran's nuclear program mounted after IAEA inspectors found traces of highly enriched uranium at two Iranian sites. Iran said the uranium was already on equipment imported from abroad.

But the report leaked Tuesday noted continued inconsistencies, including different levels of uranium enrichment and varying isotope "fingerprints" -- both casting doubt on Tehran's assertion that the traces of enriched uranium were already on equipment it bought second hand from abroad.

Without directly naming Pakistan, the source of the equipment, the report said that that the provider state disputes being the source of all the enriched uranium traces found in Iran -- potentially strengthening arguments that Tehran itself enriched uranium, something it denies.

Iran agreed last year, under international pressure, to suspend uranium enrichment and allow intrusive inspections of its nuclear facilities, and the report suggested that pledge has been generally met.

But while, "the Agency continues to make progress in gaining a comprehensive understanding of Iran's nuclear program ... a number of issues remain outstanding," the report said. Besides the source of the enriched uranium samples, it said "important information" about Iran's advanced centrifuge program "has frequently required repeated requests, and in some cases continues to involve changing or contradictory information."

One example cited was the reversal of previous denials that it bought centrifuge parts from abroad.

Answering all outstanding questions "is of key importance to the agency's ability to provide the international community with the required assurances about Iran's nuclear activities," it said.

The United States has pushed for Security Council involvement for months, asserting that Iran is in breach of the Nuclear Nonproliferation Treaty. Bolton said that the United States and its European allies were closing ranks on taking a harder line on Iran.

Bolton said outside the conference that the United States was convinced Iran wants to acquire nuclear arms. "We obviously haven't yet gotten to the bottom of the program."

Key European allies France, Germany and Britain, in particular, have advocated a softer line, arguing that persuasion was less risky than confrontation. But Vienna-based European diplomats have in recent days suggested that -- with key questions still unanswered -- patience with Iran was wearing thin.

Bolton acknowledged that the June 14 board meeting might still not agree to haul Iran before the Security Council, saying "exactly when and how we get there is still not agreed upon".

But "I think there's a realization that ... we should not allow the Iranians to divide us or divert us."

(China Daily via agencies, June 2, 2004)