Iran had ruled out responding this week to international incentives to suspend disputed portions of its nuclear program.

"The indications are that Iran's response has been disappointing and incomplete," Rice had reporters aboard her flight here.

Any real move to punish Iran at the Security Council is a long way off, but the group said it will seek an initial resolution requiring Iran to suspend its uranium enrichment. Debate could begin as soon as next week.

If Iran does not comply, the group said it would then seek harsher action. The group's short statement give no specifics, but it cited a section of the world body's charter that could open the door to economic or other sanctions.

The group said it could stop the Security Council actions at any time should Iran cooperate. The U.N.'s nuclear watchdog agency has already told Iran it must put uranium enrichment and related disputed activities on hold, and doing so is the condition for opening negotiations on the incentives package presented to Iran last month.

Enrichment can produce fuel for a civilian reactor or fissile material for a bomb.

The European Union offered Iran a similar package of economic and trade incentives last year, but Iran rejected the proposal and ramped up nuclear activities including uranium enrichment that it had suspended during the European talks.

More is on the line now that Iran has moved closer to being able to build a nuclear weapon, and the United States has offered to bargain face-to-face.