Iran seems determined to defy international demands to control its disputed nuclear program, so it is time for the U.N. Security Council to act, Secretary of State Condoleezza Rice said Thursday.

"Is the Security Council going to be credible?" Rice asked after meetings with NATO foreign ministers.

Tehran faces a Friday deadline from the Security Council to stop enriching uranium, a process that can lead either to nuclear power for electricity or to development of weapons. "It's pretty clear Iran is not going to meet those requirements," Rice said. "When that happens the international community, represented by the Security Council, is going to have a choice."

Quick action by the council to impose economic or punitive sanctions seems remote because of splits among its members. The United States is pressing for a strong response and Rice wants such steps to remain an option.

The United States and European allies accuse Iran of hiding ambitions to build a bomb behind a legitimate energy program. Iran denies it but says it must retain control of sensitive nuclear technology, including uranium enrichment.

The United States has long sought the Security Council review now under way, but the powerful U.N. body is divided over what to do next.

Russia and China, both veto-wielding permanent members of the Security Council, oppose sanctions against Iran. The United States, France and Britain say if Tehran does not meet the deadline, they will make the enrichment demand and other conditions compulsory.

"In order to be credible the Security Council has to act," Rice told reporters at the NATO session. "The Security Council is the primary and most important institution for the maintenance of peace and stability and security and it cannot have its word and its will simply ignored by a member state."

U.S. diplomats are gauging support in Europe for another course: A network of independent sanctions and restrictions, such as a travel ban on Iranian leaders, that might persuade the clerical leadership to back down.

Many European countries have already indicated a willingness to take such measures on their own, such as asset seizures and potential export bans.

The U.S. already has a near total ban on economic and diplomatic contact with Iran, but European nations and Russia maintain broad ties. Russia is a major commercial partner of Tehran, including exporting its oil.

Earlier Thursday, Russian President Vladimir Putin said the Security Council should not assume responsibility for the Iranian nuclear issue.

"It's still too early to run ahead and say what decision we might take together," he said. "The main thing is ... that whatever decision is taken is a consensus decision."

Rice was making the case for continued pressure as part of two days of meetings with European colleagues that followed her unannounced trip to Iraq this week. In Baghdad, Rice and Defense Secretary Donald H. Rumsfeld endorsed newly selected Iraqi leaders who the United States hopes can regain traction against a violent insurgency and spreading sectarian killings.

Rice tried to reassure Europeans that the United States is not planning military action against Iran.

"I have been talking with my colleagues around the world about the diplomatic agenda regarding Iran," Rice said. "The president of the United States doesn't take any of his options off the table but we are committed to a diplomatic course" that should succeed "with enough unity and with enough strength and enough common purpose."