President Bush said he will support a new UN resolution authorising war on Iraq, announced "the game is over" for Iraqi President Saddam Hussein, and challenged the Security Council to stand up to Iraqi defiance.
With Secretary of State Colin Powell at his side, President Bush increased pressure on the Security Council, signalling the United States is prepared to go to war with a coalition of like-minded nations with or without UN backing.
"Saddam Hussein has made Iraq into a prison, poison factory and a torture chamber for patriots and dissidents. Saddam Hussein has the motive and the means and the recklessness and the hatred to threaten the American people. Saddam Hussein will be stopped," President Bush said.
Security Council members France, Russia and China have expressed reservations about a war against Iraq, saying UN weapons inspections should be given more time. Mr Powell gave a presentation on Wednesday alleging systematic Iraqi concealment of suspected weapons of mass destruction and Iraqi ties to terrorist groups.
President Bush predicted a "last-minute game of deception" from Saddam but said it will not work.
"The game is over. All the world can rise to this moment. The community of free nations can show that it is strong and confident and determined to keep the peace. The United Nations can renew its purpose and be a source of stability and security in the world," he said.
Testifying before the Senate Foreign Relations Committee on Capitol Hill, Mr Powell said he thought the showdown with Iraq "will start to come to a head" when top UN weapons inspectors return next week from a trip to Baghdad and report to the UN Security Council on February 14th.
British Prime Minister Mr Tony Blair said in London he was confident of pulling France, Russia and other war doubters behind military action against Iraq if it was proved to be in breach of its disarmament obligations.
The Bush administration, facing a wary public at home about the prospect of war and uneasiness abroad, has support for war from Britain, Italy, Spain, Portugal, Denmark, Poland, Hungary and the Czech Republic and most Eastern European nations as well as Australia.
Mr Powell insisted his UN presentation was starting to sway doubting allies. He said he thought there may be more support "than some might think" for a second UN resolution to disarm Iraq by force.