Rice Warns Iran It Risks Further U.N. Sanctions

Russia and China are also resisting a tough reaction. Russia's U.N. ambassador, Vitaly Churkin, said, "We should not lose sight of the goal, . . . to accomplish a political outcome of this problem."

Thursday's six-page report concluded that "Iran has not suspended its enrichment related activities." The report provided no evidence that Iran is trying to develop nuclear weapons, as President Bush asserts, but inspectors said Iran's lack of voluntary cooperation with its investigation made it impossible to rule out that such efforts were underway.

The report detailed progress Iran has made in the past two months installing several hundred centrifuges for industrial-scale enrichment at its largest nuclear facility in the town of Natanz. The Iranians have been enriching low levels of uranium suitable for a nuclear energy program, not bombs, in other centrifuges set up more than a year ago at Natanz's research center.

IAEA inspectors said Iran had not provided any new information on the history of its nuclear program, which began in secret in 1987. Inspectors also received no answers to questions raised by documents obtained by U.S. intelligence in 2004 that suggest Iran was trying to develop a missile capable of carrying a nuclear warhead and was considering plans for a second uranium-conversion facility.

Despite the lack of information in the report, no official, in Washington or Europe, suggested that Iran's current work meant it will acquire nuclear weapons in the near future.

"Their nuclear program is not forging ahead," said a senior European diplomat. "Some of that is a result of the sanctions and the international pressure on them and some of it is because of their own technical difficulties in putting the program together."

Staff writers Glenn Kessler and Karen DeYoung contributed to this report.