Congress has given President Bush the authority to use military force against Iraq in a major policy victory for the White House.
The Senate approved the measure 77-23 early Friday morning at the end of a rocky week-long debate. The House voted for the resolution Thursday afternoon, 296-133.
Because the Democratic-led Senate approved the House version of the measure without changing a word, it now goes directly to Bush for his signature.
The resolution gives Bush the power to use American military force to enforce existing United Nations Security Council mandates that Iraqi leader Saddam Hussein dispose of his weapons of mass destruction.
It encourages Bush to seek U.N. cooperation in such a campaign, but does not require it.
Sen. Robert Byrd, D-W.Va., the most outspoken Senate foe of the resolution, accused Congress of "handing the president unchecked authority."
Bush spoke after the House had passed the bill.
"The House of Representatives has spoken clearly to the world and to the United Nations Security Council: The gathering threat of Iraq must be confronted fully and finally," the president said.
The president has repeatedly stressed, however, that no final decision on whether to launch a military strike against Iraq has been made.
While Bush hailed the strong House showing, a majority of House Democrats voted against the resolution -- even though their leader, Dick Gephardt of Missouri, was one of its authors.
"The issue is how to best protect America. And I believe this resolution does that," Gephardt said.
The Senate approval of the resolution came after it voted 75-25 to end delaying tactics. It also voted down a series of efforts to weaken or block the resolution, as did the House.
The administration got a big boost Thursday morning when Senate Majority Leader Tom Daschle suddenly announced he was putting aside his misgivings to support the president.
"I believe it is important for America to speak with one voice," said Daschle, D-S.D. "It is neither a Democratic resolution nor a Republican resolution. It is now a statement of American resolve and values."
But some influential Democrats remained opposed.
"The power to declare war is the most solemn responsibility given to Congress by the Constitution," said Sen. Edward M. Kennedy, D-Mass. "We must not delegate that responsibility to the president in advance."
The resolution gives the president wide latitude in defending the United States against the "continuing threat" posed by Baghdad.
In a concession to Democrats, it encourages that all diplomatic means be exhausted before force is used, and requires reports to Congress every 60 days once action is taken.
Bush has said he hopes to work with the United Nations, but wanted congressional authority to act independently if necessary. The strong congressional backing he was receiving could bolster U.S. efforts before the U.N. Security Council.
At the State Department, spokesman Richard Boucher said "talks are progressing" at the Security Council on wording of a strong new resolution to disarm Iraq that all five veto-holding permanent members can support.
The United States and Britain continue to encounter resistance from the three other key members: France, Russia and China.
The president on Thursday telephoned Gephardt and House Speaker Dennis Hastert, R-Ill., to thank them for the House vote, then spoke to reporters at a hastily arranged news conference.
"Today's vote ... sends a clear message to the Iraqi regime: You must disarm and comply with all existing U.N. resolutions or [you] will be forced to comply. There are no other options for the Iraqi regime. There can be no negotiations. The days of Iraq acting as an outlaw state are coming to an end," the president said.
The war resolution comes nearly 11 years after Congress voted to give Bush's father similar powers to confront Saddam.
In the earlier instance, however, an international coalition was already in place to drive Iraqi invaders out of Kuwait. The current Bush administration has faced resistance from allies in its efforts to form a similar alliance.
In the House, 126 of the chamber's 208 Democrats voted against the war resolution.
Still, that was stronger support than the first President Bush received in 1991 when the then-Democratic-controlled House voted 250-183 to authorize force against Iraq.
House Democrats urged the president to work closely with the United Nations before going it alone against Iraq.
"Completely bypassing the U.N. would set a dangerous precedent that would undoubtedly be used by other countries in the future to our and the world's detriment," said Gephardt.
The House earlier rejected, by 270-155, the main challenge to the White House-backed resolution: a proposal, backed by a majority of Democrats, that obliged the president to return to Congress for a second vote on the use of American force against Iraq if he decides that cooperative efforts with the United Nations are futile.
Rep. John Spratt, D-S.C., said that without a multilateral approach, "this will be the United States versus Iraq and in some quarters the U.S. versus the Arab and the Muslim world."
The Senate also turned aside efforts to put more checks on the president's war-making authority. It rejected, 75-24, a proposal by Senate Armed Services Committee Chairman Carl Levin, D-Mich., that was similar to the Spratt proposal in the House.
On the key 75-25 Senate vote to draw debate to a close, 28 Democrats joined 47 Republicans in voting for the measure. Only two Republicans voted against it: Lincoln Chaffee of Rhode Island and Arlen Specter of Pennsylvania.
In the closing hours of debate, Sen. Hillary Rodham Clinton, D-N.Y., said the decision to back the resolution was "the hardest decision I've ever had to make, but I cast it with conviction. I want this president, or any future president, to be in the strongest possible position to lead our country, at the United Nations or at war."
Meanwhile, retired Marine Gen. Anthony Zinni, former head of U.S. Central Command, said Thursday that the Bush administration seems unnecessarily rushed about taking on Iraq.
Zinni, a former U.S. envoy to the Mideast for the Bush administration, said he considers Saddam "deterrable and containable at this point."
"I'm not convinced we need to do this now," Zinni said at a foreign-policy forum.
The Associated Press contributed to this report.