President Bush is vowing to ``use all the tools at our disposal'' to bring down Iraqi President Saddam Hussein.

Taking a now-familiar hard line but not specifically saying he intends to use force, Bush is again stirring speculation that the United States may be preparing an armed attack.

Describing himself as a patient person, Bush said at a White House news conference Monday that he was convinced ``the world would be safer, more peaceful if there is a regime change'' in Iraq.

Bush called reports of preparation for an attack speculation and he mildly admonished lower-level U.S. officials not to engage in it.

Still, he said, ``It is the stated policy of this government to have a regime change ... and we'll use all the tools at our disposal to do so.'' He dismissed the question of whether he would make the move in his first term as hypothetical.

Earlier, the State Department demanded that Iraq ``come clean'' on its suspected weapons programs and confirmed it was conferring with Middle East governments on the threat that it said Iraq poses to its neighbors and the world.

``It's a major concern,'' State Department spokesman Richard Boucher said.

Plans to oust Saddam with the cooperation of other Arab governments are known to be under consideration within the administration.

Bush has deflected questions about a possible U.S. attack on a regime he branded in January as part of an ``axis of evil.'' His standard reply is that no war plan is on his desk.

However, he has not denied that plans are being prepared.

The rhetoric at the State Department followed last week's failure of the United Nations to persuade Iraq to permit the return of U.N. weapons inspectors after a 3 1/2-year lapse.

U.N. Secretary-General Kofi Annan said the Iraqis needed to consult with officials in Baghdad and no date was set for another round of talks.

``There has been some movement, but obviously not enough,'' Annan said Friday.

On Monday, the Security Council again urged the Iraqi government to let inspectors return at once and unconditionally.

Boucher said he would not speculate about a possible attack on Iraq. He then assailed the Baghdad government for failing to ``come clean for the world'' and open suspect sites to the United Nations.

Iraq's refusal raises suspicions about what the government is up to, Boucher said.

``We certainly do talk to governments in that region all the time about Iraq,'' he said. ``Iraq is a threat to regional security, to the nations in the region as much as anybody else, and their development of weapons of mass destruction continues to threaten everybody in the region, as well as the rest of the world.''

The State Department on Tuesday will host a meeting of groups seeking to overthrow Saddam. Another meeting will be held soon in London.

So far, these opposition groups have failed to make a dent in Saddam's rule. Neither has a succession of U.S. presidents and secretaries of state and defense.