The United States is not preparing for war with Iran, Secretary of State Condoleezza Rice said on Friday in response to the UN nuclear watchdog chief's remarks against using force to stop Iran's nuclear program.

"The president of the United States has made it very clear what our policy is. That policy is supported by all the members of his cabinet and by the vice president of the United States," Rice said referring to U.S. opposition to Iran's nuclear activities.

Her words came after talks with Spanish Foreign Minister Miguel Moratinos in Madrid. Earlier, the U.N. nuclear watchdog agency chief Mohamed ElBaradei had cautioned against military action to halt Iran's nuclear program.

"I have no brief other than to make sure we don't go into another war or that we go crazily into killing each other. You do not want to give additional argument to crazy people who say 'let's go and bomb Iran'," he told BBC radio.

"We have a diplomatic choice, but it's only going to succeed if we are absolutely clear with the Iranians, not muddying the message in any way," said Rice.

Also in Madrid, nuclear talks between negotiators for Iran and the European Union on Thursday ended without an announcement of any breakthrough.

Two rounds of sanctions have been ordered by the U.N. Security Council over Iran's nuclear program and a third round has been proposed by Washington. Iran has pledged to cooperate with the International Atomic Energy Agency (IAEA).

The United States has accused Iran of trying to develop nuclear weapons under the cover of a civilian nuclear program. However, Iran has said its nuclear program is for peaceful purposes only.