U.S. Says Iran Must Cooperate on Nuclear Program

President Bush said the United States and the European Union's "big three members" -- France, Britain and Germany -- "expect there to be full disclosure, full transparency of their nuclear weapons programs."

White House national security adviser Condoleezza Rice further warned, "This regime has to be isolated in its bad behavior, not 'engaged.'"

Rice said the administration was working with the Europeans and other International Atomic Energy Agency members on "a very tough set of resolutions" demanding Iranian cooperation.

"Iran is going to be confronted," Rice told Fox News, adding that the resolutions should be ready for consideration in September. If Iran refused to cooperate, she said, "They're going to be isolated."

Bush told reporters at the White House, "We are working with our friends to keep the pressure on the mullahs to listen to the demands of the free world."

The warnings came two days after Iran said it had resumed building nuclear centrifuges, which Washington says are intended to enrich uranium to weapons grade for use in bombs.

Iran's decision backtracks from a pledge in October to Britain, France and Germany to suspend all uranium enrichment-related activities.

Rice brushed aside a question about whether France would go along with U.S. plans to increase pressure.

"The French and the Germans and the British have been very clear to the Iranians that the activities that they're currently engaged in, or say that they are going to resume, are unacceptable, and we just have to keep working with the French and the British and the Germans to make certain that they stick to that position," Rice said.

"It's been our position all along that the Iranians are dangerous in this regard, and that the international community has got to be tough and steadfast here,'' she added.

Iran insists it needs enriched uranium for power stations being built to meet booming domestic demand for electricity.

Secretary of State Colin Powell warned Iran last week that its case was increasingly likely to be referred to the sanctions-imposing U.N. Security Council for failing to meet IAEA commitments.

Washington says Iran's nuclear energy program is a cover for development of nuclear weapons.