Joined by about 100 lawmakers on Wednesday, President Bush signed a congressional resolution authorizing him to go to war with Iraq if Saddam Hussein doesn't immediately disarm his nation's weapons of mass destruction.

"The resolution I'm about to sign symbolizes the united purpose of our nation, expresses the considered judgment of the Congress and marks an important event in the life of America," Bush said just before penning his name on the resolution in an East Room ceremony.

"The 107th Congress is one of the few called by history to authorize military action to defend our nation in the cause of peace," he said.

The resolution, passed by the House and Senate last week, makes clear that Saddam's defiance of any one of 16 U.N. Security Council resolutions puts him at odds with the international community, and the United States will respond to that threat.

It also urges the president to seek support from the United Nations before taking any action, though the president is not required to get support before beginning military maneuvers.

The resolution was not significantly altered from the president's original draft. However, it does require the president to notify Congress before or within 48 hours after an attack that further diplomatic approaches would not have protected U.S. security and to explain to Congress how the military action will not hurt the war on terror.

"With this resolution, Congress has now authorized the use of force. I have not ordered the use of force. I hope the use of force will not become necessary. Yet confronting the threat posed by Iraq is necessary by whatever means that requires," Bush said.

Before signing the bill, the president said Saddam has gone to great lengths to deceive U.N. weapons inspectors and that Iraq would be a much better place if Saddam were not in power.

"Our desire is to help Iraqi citizens find the blessings of liberty within their own culture and their own traditions. Iraqi people cannot flourish under a dictator that oppresses them, threatens them. Gifted people of Iraq will flourish if and when oppression is lifted," he said, adding a promise to help Iraq "reform and prosper" after a new government is installed.

On Tuesday, Saddam tried to convince the world that he is the rightful leader of Iraq, holding a referendum to demonstrate the people's freedom. The Iraqi population voted by a 100 percent margin to give him another seven-year term. No other candidates were in the running and voters, required to go to the polls, also had to write their names and addresses on the ballots.

In the East Room, Bush was backed by a bipartisan group of lawmakers, though House Democratic Leader Dick Gephardt of Missouri and Senate Majority Leader Tom Daschle of South Dakota were conspicuously absent.

Gephardt took a lot of heat for negotiating the language of the resolution in the House, which was much tougher than many Democrats wanted and which undercut a move in the Senate by Daschle and others to force the president to work more through the United Nations than the White House wanted.

In the end, the House voted 296-133 and the Senate 77-23 to support the resolution.

Gephardt aides said the minority leader's travel schedule was keeping him away, but just Tuesday he ratcheted up strong criticism of the Bush administration and Republicans on the economy.

Daschle's daughter gave birth early Wednesday morning. He and Gephardt were both scheduled to be on Capitol Hill later in the day to attend to legislative business.

House and Senate lawmakers ended up voting for the tougher language by a much wider margin than the resolution that authorized the Persian Gulf War in 1991, even though then-President George H.W. Bush had built a much broader international coalition in support of that war.

The United States is not making nearly as much headway with the international community as it did in 1991, though the administration continues to push for a strong resolution that compels Iraq to submit to unconditional weapons inspections.

The U.N. Security Council was debating the resolution on Wednesday, but resistance has been met by several nations, most urgently China, Russia and France, who have veto power on the Security Council.

The Bush administration has argued that Saddam is a threat to the international community because of his willingness to deliver biological and chemical weapons to terrorist forces, which have been re-constituting themselves since their expulsion from Afghanistan nearly a year ago.

The president's speech before the signing was an address to the international community as much as it was to the members of the audience.

"If Iraq gains even greater destructive power, nations in the Middle East would face blackmail, intimidation or attack. Chaos in that region would be felt in Europe and beyond. And Iraq's combination of weapons of mass destruction and ties to terrorist groups and ballistic missiles would threaten the peace and security of many nations," he warned.

On Wednesday, French President Jacques Chirac said he sees no link between Al Qaeda and Iraq. French officials have said that they do not want a resolution calling for military force against Saddam if he does not comply with inspectors.

They would prefer that a second resolution authorizing force in the case of non-compliance be debated separately, a position backed by the Russians, who were making their case at the United Nations as the president spoke.

"The American variant of the resolution on Iraq has not undergone changes. It is unacceptable and Russia cannot support it," Yuri Fedotov said, according to the news agency Interfax.

However, the French proposal contains "many positions that Russia shares," Fedotov was quoted as saying.

Later in the day, the president met with Israeli Prime Minister Ariel Sharon. The two discussed U.S. measures to protect Israel should Saddam use chemical and biological weapons against Israel in retaliation for a U.S. attack. Israel withheld return fire in 1991 after Saddam dropped dozens of Scud missiles on the nation, but has said it would be willing to retaliate this time.

Bush asked Israel to refrain from action that could inflame the Arab world and undermine support for war against Iraq and the war against terrorism.

After the meeting, Bush did say that if Iraq attacked Israel tomorrow, then he would expect the prime minister to respond to defend his country.

Fox News' Wendell Goler and The Associated Press contributed to this report.