Hours earlier, the House approved an identical resolution, 296-133. 
The president praised the congressional action, declaring "America speaks with one voice." 

"The Congress has spoken clearly to the international community and the United Nations Security Council," Bush said in a statement. "Saddam Hussein and his outlaw regime pose a grave threat to the region, the world and the United States. Inaction is not an option, disarmament is a must." 

The resolution requires Bush to declare to Congress either before or within 48 hours after beginning military action that diplomatic efforts to enforce the U.N. resolutions have failed. 

Bush also must certify that action against Iraq would not hinder efforts to pursue the al Qaeda terrorist network that attacked New York and Washington last year. And it requires the administration to report to Congress on the progress of any war with Iraq every 60 days. 

The measure passed the Senate and House by wider margins than the 1991 resolution that empowered the current president's father to go to war to expel Iraq from Kuwait. That measure passed 250-183 in the House and 52-47 in the Senate. 

The Bush administration and its supporters in Congress say Saddam has kept a stockpile of chemical and biological weapons in violation of U.N. resolutions and has continued efforts to develop nuclear weapons. Bush also has argued that Iraq could give chemical or biological weapons to terrorists. 

Iraq has denied having weapons of mass destruction and has offered to allow U.N. weapons inspectors to return for the first time since 1998. Deputy Prime Minister Abdul Tawab Al-Mulah Huwaish called the allegations "lies" Thursday and offered to let U.S. officials inspect plants they say are developing nuclear, biological and chemical weapons. 

"If the American administration is interested in inspecting these sites, then they're welcome to come over and have a look for themselves," he said. 

The White House immediately rejected the offer, saying the matter is up to the United Nations, not Iraq. 

Resolution sharply divides Democrats
The Senate vote sharply divided Democrats, with 29 voting for the measure and 21 against. All Republicans except Sen. Lincoln Chafee of Rhode Island voted for passage. 

Ahead of the vote, Senate Majority Leader Tom Daschle announced Thursday morning he would support Bush on Iraq, saying it is important for the country "to speak with one voice at this critical moment." 

Daschle, D-South Dakota, said the threat of Iraq's weapons programs "may not be imminent. But it is real. It is growing. And it cannot be ignored." However, he urged Bush to move "in a way that avoids making a dangerous situation even worse." 

Daschle had expressed reservations about a possible U.S. attack on Iraq, and he was not part of an agreement between the White House and other congressional leaders framing the resolution last week. 

Sen. Robert Byrd, D-West Virginia, attempted Thursday to mount a filibuster against the resolution but was cut off on a 75 to 25 vote. 

Byrd had argued the resolution amounted to a "blank check" for the White House. 
"This is the Tonkin Gulf resolution all over again," Byrd said. "Let us stop, look and listen. Let us not give this president or any president unchecked power. Remember the Constitution." 

But Sen. John McCain, R-Arizona, said the United States needs to move before Saddam can develop a more advanced arsenal. 

"Giving peace a chance only gives Saddam Hussein more time to prepare for war on his terms, at a time of his choosing, in pursuit of ambitions that will only grow as his power to achieve them grows," McCain said. 

In the House, six Republicans -- Ron Paul of Texas; Connie Morella of Maryland; Jim Leach of Iowa; Amo Houghton of New York; John Hostettler of Indiana; and John Duncan of Tennessee -- joined 126 Democrats in voting against the resolution. 

Minority Leader Richard Gephardt, D-Missouri, said giving Bush the authority to attack Iraq could avert war by demonstrating the United States is willing to confront Saddam over his obligations to the United Nations. 

"I believe we have an obligation to protect the United States by preventing him from getting these weapons and either using them himself or passing them or their components on to terrorists who share his destructive intent," said Gephardt, who helped draft the measure. 

But Rep. Dennis Kucinich, D-Ohio, said the 133 votes against the measure were "a very strong message" to the administration. 

"All across this land Americans are insisting on a peaceful resolution of matters in Iraq," he said. "All across this land, Americans are looking towards the United States to be a nation among nations, working through the United Nations to help resolve this crisis."