Colum Lynch, Washington Post - The U.N. Security Council voted unanimously Saturday to restrict Iran's trade in sensitive nuclear materials and to freeze the assets of 22 Iranian officials and institutions linked to the country's most controversial nuclear programs.

The council's action culminated more than three years of diplomatic efforts by the United States to have Iran sanctioned for expanding its enrichment of uranium. But Russia, a close commercial partner of Iran, stripped the resolution of some of its toughest measures, including a travel ban on officials linked to the nuclear programs.

The resolution demands that Iran immediately suspend its enrichment program and its reprocessing of spent nuclear fuel within 60 days or face additional U.N. penalties. It calls on Tehran to begin talks with the Security Council's five permanent powers and Germany to allay international suspicions that it may be pursuing nuclear weapons.

While some critics suggested the council resolution was too weak to compel Iran to change its behavior, the Bush administration -- which favored tougher measures -- said it was still pleased with the final version, saying that it furthers Iran's growing international isolation.

U.S. Undersecretary of State Nicholas Burns called the vote "humiliating" for Iran. He added that the vote "would open the way for further action outside the Security Council," and that the United States would continue to press Japan, European governments and international financial agencies to impose their own penalties on Iran.

Iranian U.N. Ambassador Javad Zarif denounced the council's "groundless punitive measures," and denied that his country had any intention of developing nuclear weapons. He said the council's failure to sanction Israel, whose prime minister inadvertently suggested this month that his country is a nuclear power, proves its bias against Iran.

Iran has the right under the 1970 Nuclear Non-Proliferation Treaty to produce nuclear energy as long as it forswears the pursuit of nuclear warheads. But in July, the Security Council, citing Iran's history of violating the pact, adopted a resolution that required Tehran to suspend nuclear enrichment and reprocessing by Aug. 31 or face sanctions. Iran refused to comply with the demand.

The United Nations' nuclear watchdog, the International Atomic Energy Agency, maintains that a two-decade "policy of concealment" by Iran's nuclear scientists has helped fuel such suspicions. But it cannot prove that Iran has ever diverted nuclear fuel to a weapons program.

The resolution will freeze the assets of 10 Iranian officials, including the directors of Iran's main nuclear facilities and the commanders of the Revolutionary Guard Corps and the Air Force, linked to the nuclear programs. The asset freeze also applies to 12 institutions, including Iran's Atomic Energy Organization.

The resolution also calls for a ban on trade related to "nuclear missile delivery systems" and demands Iran halt work on a heavy-water research reactor at Arak, 150 miles south of Tehran.