Officials here say it was not difficult to negotiate the resolution, given a growing recognition among the United States' European allies that Iranian cooperation with the international community on its nuclear program has been less-than-complete.

The compromise draft is understood to note with serious concern that an Iranian declaration of its nuclear activities last October was not the full accounting that the U.N. agency had sought.

It condemns in particular Iran's failure to report its possession of critical technologies including plans for advanced centrifuges for making weapons-grade uranium.

But it praises some Iranian actions including its stated acceptance of snap nuclear inspections. And it defers at least until the next IAEA meeting in June a referral of the matter to the U.N. Security Council, where Tehran could face economic sanctions.

Officials say the draft is to be sent to the various capitals for additional comments and then shared with other members of the 35-nation IAEA board, which acts by consensus vote.

They say it balances the U.S. conviction that Iran has a secret nuclear weapons program, with Western Europe's view that there is room for "constructive engagement" with Tehran to clear up questions about its nuclear activities.

At a news briefing, State Department spokesman Richard Boucher said that with the resolution, the United States wants to send a strong signal to Iran that it cannot refuse to cooperate with the IAEA with impunity. "We think it's clear that Iran has not made any decision, any strategic decision, to abandon a nuclear weapons effort. We're concerned about the pattern of Iranian behavior that's documented in the reports over the last year from the Director-General [Mohamed] El-Baradei. These show grudging, partial Iranian cooperation, only when confronted by the International Atomic Energy Agency with compelling evidence of an undeclared program. That pattern is continuing," he said.

Mr. Boucher said the United States hoped to draw a contrast at the Vienna meeting between Iran's approach and that of Libya, which has fully disclosed and given up its nuclear weapons ambitions and deserves the commendation of the IAEA board.

A senior diplomat who spoke to reporters here said the United States agreed not to seek a referral of Iran to the Security Council because of an expectation that IAEA inspectors will find more evidence of weapons activity in the coming months, and that perhaps European envoys can persuade Iran to make good on a pledge to them last year to suspend uranium enrichment activity.

He said if Iran continues down the course it has been on, then a referral for sanctions "would be a logical conclusion."