"The Iranians just need to know that the free world is working together to send a very clear message: Don't develop a nuclear weapon. And the reason we're sending that message is because Iran with a nuclear weapon would be a very destabilizing force in the world."

Mr. Bush says he looks forward to further discussions with European leaders about Iran's nuclear ambitions:

"It is important we speak with one voice."

Britain, France, and Germany are currently in negotiations with Iran about its nuclear program. The Europeans are attempting to persuade Iran to permanently stop all uranium enrichment activities in return for economic incentives. Enriched uranium is a key element in the production of nuclear weapons.

Secretary of State Condoleezza Rice says that the United States appreciates European efforts to convince the Iranians "to forswear. . . .any effort to build nuclear weapons under the cover of civilian nuclear power and to adhere to their international obligations:"

"They [the Iranians] are being given an opportunity to demonstrate that they are prepared to live up to those obligations. So I think the message is there. The Iranians need to get that message. And we can certainly always remind them that there are other steps that the international community has at its disposal should they not be prepared to live up to these obligations."

Secretary of State Rice says referring the issue to the United Nations Security Council with the possibility of sanctions "looms" if Iran fails to fulfill its commitments. The Iranian government needs to realize, says Ms. Rice, that negotiations with the Europeans "are not going to be a kind of way station where they're allowed to continue their activities." "There's going to be an end to this," says Ms. Rice.