"Democrats waiting for the U.N. to act?" a chuckling Bush said. "Seems like, to me, that if you're representing the United States, you ought to be making decisions based on what's best for the United States.
"If I were running for office," he added, "I'm not sure how I would explain to the American people. You know, 'Vote for me, and oh, by the way, on a matter of national security, I'm going to wait for somebody else to act.'"
Coming a day after his speech demanding quick U.N. action to disarm Iraq, Bush's comments signaled that though he has consulted Congress and world leaders, he wants a speedy timetable.
The deadline for Saddam Hussein's regime to comply, Bush said, should be "days and weeks, not months and years."
Still, the president suggested, it is "highly doubtful" that Hussein will yield to pressures and avoid a military confrontation.
In his caustic remarks about Democrats, Bush was responding to those who say they will resist Bush's call for a speedy congressional resolution authorizing force against Iraq. Some lawmakers say Congress should not be asked to vote on whether to authorize military action before knowing what the international consensus is.
"We ought to speak with one voice, urging the U.N., rather than being in any way speculative or divisive," said Sen. Carl Levin, a Michigan Democrat who chairs the Senate Armed Services Committee. Levin said he is considering drafting a resolution that would urge the U.N. to act but would not give Bush formal authority to attack Iraq.
Several senior Democrats seem to be pushing a two-stage role for Congress in which lawmakers would first vote - possibly as early as next week - to urge U.N. action. Once the United Nations has chosen a course of action, Congress would consider a resolution on use of force.
"If he wants a resolution supporting his speech of [Thursday], that's easy to pass," said Sen. Richard J. Durbin, an Illinois Democrat, referring to Bush. "If he wants an open-ended authorization to go to war, that's not so easy to pass."
Bush was backed by top Republicans in Congress, who called for swift action on a resolution to allow force. They said that not doing so would weaken Bush's position as he lobbies other international leaders.
Bush received some encouragement at the United Nations. Secretary of State Colin L. Powell emerged from a meeting with leaders from the other permanent members of the Security Council - Russia, China, Britain and France - to say he had won their agreement that Hussein poses a threat to international security.
And foreign ministers of the five nations released a joint statement saying that Iraq's defiance of past U.N. resolutions "is a serious problem," and that discussions had begun over how the Security Council "can tackle the problem to implement all the resolutions."
Some nations that have adamantly opposed the use of force - including Russia, which has economic ties to Hussein's regime - seemed to move closer to Bush's hard-line position.
Foreign Minister Igor S. Ivanov of Russia said that "should Iraq refuse to cooperate with the Security Council, the Iraqi leadership will have to assume responsibility for all possible consequences."
Bush made clear that if the United Nations did not act quickly or if Hussein did not abide by fresh demands, the United States would be ready to oust his regime, with or without support of other countries.
In his meetings yesterday with foreign leaders at the United Nations, Powell began working on the key points for a U.N. resolution that he said would set deadlines for Hussein.
Still, serious obstacles to a broad international coalition against Iraq remain. Many world leaders who expressed support for Bush's speech said nothing about backing any military campaign.
And one European diplomat said that U.S. officials will have to work to persuade Russia and China - which, as permanent members of the Security Council, can veto any resolution - to approve strict deadlines for Iraq.
A senior State Department official said Powell argued during his meeting that a resolution must record Iraq's violation or previous resolutions, say what is expected of Iraq, set a deadline and detail what steps the council will take should Iraq not comply.
President Hosni Mubarak of Egypt, who has joined other Arab leaders in expressing staunch opposition to a U.S. military campaign in Iraq, lent some support to Bush.
Mubarak publicly backed the president's call for Iraqi disarmament and urged Hussein to fully comply with U.N. resolutions.
"I welcome the door the United States opened for the United Nations, especially the Security Council, to play a pivotal role," Mubarak, a moderate Arab leader and key U.S. ally, said in an interview with Egypt's Middle East News Agency. "I call upon the Iraqi leadership to seize this opportunity and avoid serious repercussions."
Mubarak and other Arab leaders have said they fear that a war in Iraq would destabilize the Middle East, a region facing unrest as the Israeli-Palestinian conflict rages on.
Iraqi Trade Minister Mohammed Mahdi Saleh vowed that Iraq would attack Israel if it joined in an effort to remove Hussein. During the 1991 gulf war, Iraq fired several dozen Scud missiles into Israel. Israel did not retaliate, but Israeli officials have said they would respond if their country is attacked by Iraq again.
In an interview on the Saudi-owned MBC television network, Iraqi Deputy Prime Minister Tariq Aziz said Baghdad did "not accept Bush's conditions," including U.N. resolutions demanding that weapons inspectors be allowed back into Iraq.
The official said he did not know whether Iraq had such material, perhaps left over from its secret nuclear program more than a decade ago. But the official estimated that Baghdad could build a nuclear weapon within three months if it gained access to fissile material.
Though it remains uncertain that Congress will give Bush authorization he wants, White House lawyers maintain that Bush could legally invade Iraq without formal authority. One Bush aide said, though, that having Congress' backing would show that the United States is speaking with one voice, giving Bush a better chance of persuading other nations to support his stance.
Some Democrats say they are hesitant to act quickly on a decision to use force and that, while they view Iraq as a dangerous threat, they have not seen enough evidence that action is necessary immediately.
"This is very serious business - let's slow it down a bit," said Sen. Joseph R. Biden Jr., a Delaware Democrat who is chairman of the Foreign Relations Committee.
"The president is doing this the right way," Biden said in a CBS interview. But, he added, "this should be something done in a very deliberate manner."
Sun staff writer Mark Matthews and the Associated Press contributed to this article.