The foreign ministers of Britain, France, Germany, Russia and China will convene along with U.S. Secretary of State Condoleezza Rice in London next Monday for a meeting aimed at a joint approach to the issue of Iran's nuclear program. The session is a prelude to the International Atomic Energy Agency governing board meeting in Vienna later in the week.

The meeting of the five permanent members of the U.N. Security Council and Germany will be a last opportunity for the major powers to forge a common position on Iran's nuclear program before the IAEA board meeting that opens next Thursday.

The Bush administration, which maintains that Iran has a secret nuclear weapons program, wants the board to refer the matter to the U.N. Security Council for possible sanctions.

Though U.S. officials insist there are enough votes on the 35-member board for a referral, Russia and China have been resisting early action, and have said Iran should be given more time to comply with demands that it reverse recent moves toward renewing uranium enrichment.

Iran, which says its nuclear program is entirely peaceful, has made overtures to both Moscow and Beijing in advance of the IAEA meeting.

Ali Larijani speaks to media after his talks with Russian Security Council chief Igor Ivanov in Moscow

In Moscow Wednesday, Iran's chief nuclear negotiator, Ali Larijani, said Iran welcomed a long-standing Russian proposal to enrich uranium for use in Iranian power reactors. He said the idea merits further discussion, but that if Iran is referred to the Security Council, it would not engage in further discussion with Moscow.

At a news briefing, State Department Spokesman Sean McCormack said the Iranian envoy, who visits China Thursday, is only trying to avoid Security Council action and buy time while Iran prepares for large-scale uranium enrichment.

"All the while they're doing this, they are continuing to get their centrifuge operation up and running. All of this is to say they again want to have it both ways. They want to continue down the road of the behaviors that are the exact source of concern for the international community, while they continue to try to draw out discussions on those very same concerns without actually getting to any agreeable diplomatic end point," he said.

While insisting that the votes exist for a U.N. referral by the IAEA board, Bush administration officials have made no similar claim about votes on the Security Council for sanctions on Iran.

They have been vague about their intentions with regard to sanctions, and have spoken about the need to find a way to punish the Iranian authorities without causing hardships for the Iranian people.

In a talk with reporters, the U.S. ambassador to the United Nations, John Bolton, said the very fact of moving the issue to the world stage at the U.N. could prompt Iran finally to respond to international concerns.

"The issue for the Security Council in the first instance is whether we can show Iran much more unmistakably than I think that they perceive it now that their pursuit of nuclear weapons is unacceptable. And I think that simply bringing this matter to the agenda of the Security Council changes the political dynamic for them, and hopefully will increase the international pressure to get them to give up that pursuit," he said.

Mr. Bolton said if the Security Council "becomes seized" with the Iranian nuclear issue, it could strengthen the hand of the IAEA in getting Iran to back off from recent actions and comply with agency resolutions.

U.S. officials say next Monday's six-power London meeting can be expected, at least, to issue a statement calling on Iran to close down its uranium enrichment plant at Natanz, which it said earlier this month it was reopening for what were termed research purposes.