Condoleezza Rice, left, and NATO Secretary General Jaap de Hoop Scheffer at NATO headquarters in Brussels

Though the Bush administration has publicly supported the joint British, French, and German diplomatic nuclear initiative with Iran, U.S. officials have expressed impatience with the negotiation process that has been underway for more than a year.

In an interview with Fox television before beginning talks in Brussels, Ms. Rice said she does not know whether anyone has told Iran as clearly as they should what the consequences will be if it rejects European incentives for full disclosure of its nuclear program

The Secretary said the Iranians need to hear that if they are unwilling to accept the deal, then a referral of the matter to the U.N. Security Council for possible sanctions looms.

She said Iran cannot use talks with the Europeans as, what she termed, a kind of way station, where they are allowed to continue their nuclear activities, which despite Iranian denials the United States says includes a covert weapons program.