VIENNA, Austria - Iran is close to clinching a deal to clandestinely import 1,350 tons of purified uranium ore from Kazakhstan, according to an intelligence report obtained yesterday by the Associated Press. Diplomats said the assessment was heightening international concern about Tehran's nuclear activities.

Such a deal would be significant because, according to an independent research group, Tehran appears to be running out of the material, which it needs to feed its uranium-enrichment program.

The report was drawn up by a member nation of the International Atomic Energy Agency and provided to the Associated Press on condition that the country not be identified because of the confidential nature of the information.

In Washington, State Department spokesman Ian Kelly said: "The transfer of any uranium yellowcake . . . to Iran would constitute a clear violation of UNSC sanctions."

"We have been engaged with many of our international nonproliferation partners on Iran's illicit efforts to acquire new supplies of uranium over the past several years," he said.

A senior U.S. official who spoke on condition of anonymity because he was talking about confidential information, said that Washington was aware of the intelligence report, but he declined to discuss specifics.

In New York, Burkina Faso's U.N. ambassador, Michel Kafando, a cochair of the Security Council's Iran sanctions committee, referred questions about a potential deal between Iran and Kazakhstan to his sanctions adviser, Zongo Saidou. Speaking in New York, Saidou said that, as far as he knew, none of the United Nations' member nations had alerted the committee about any such allegations.

"We don't have any official information yet regarding this kind of exchange between the two countries," Saidou said. "I don't have any information; I don't have any proof."

A senior U.N. official said the Vienna-based IAEA was aware of the assessment but could not yet draw conclusions. He spoke on condition of anonymity because he was discussing confidential information. A Western diplomat from a member of the IAEA's 35-nation board said the report was causing concern among countries that have seen it and was generating intelligence chatter. The diplomat also requested anonymity because he was barred from publicly discussing intelligence information.

A two-page summary of the report obtained by the Associated Press said the deal could be completed within weeks. It said Tehran was willing to pay $450 million for the shipment.

"The price is high because of the secret nature of the deal and due to Iran's commitment to keep secret the elements supplying the material," said the summary, adding: "The deal is to be signed soon."

An official of the country that drew up the report said "elements" referred to state employees acting on their own without approval of the Kazakh government.

After-hours calls to offices of Kazatomprom, the Kazakh state uranium company, in Kazakhstan and Moscow, were not answered. Iranian nuclear officials also did not answer their telephones.

Purified ore, or uranium oxide - known as "yellowcake" - is processed into a uranium gas, which is then spun and re-spun to varying degrees of enrichment. Low enriched uranium is used for nuclear fuel, and upper-end high enriched uranium for nuclear weapons.