The 52-47 vote fell far short of the 60 needed to advance the legislation and marked the final act in an all-night session that Democrats engineered to dramatize their opposition to the war.

"Time and the American people are ... on our side," said a defiant Majority Leader Harry Reid of Nevada, who has made ending the war the Democrats' top goal since they took control of the Senate in January. "We will do everything in our power to change course in Iraq," he said moments after the vote.

Equally unyielding on the other side, Arizona Sen John McCain said, "As long as there is a prospect for not losing this war, then we must not choose to lose it."

"I do not know how I could choose any other course," said McCain, a Republican presidential contender.

The Senate's action left no doubt that Bush's decision last winter to deploy additional troops to Iraq will have at least two more months to produce results. Gen David Petraeus, the top US general in Iraq and architect of the president's latest strategy, is to deliver a report to Congress on Sept 15.

Wednesday's vote unfolded as Secretary of State Condoleezza Rice visited the Capitol for private meetings with lawmakers and the nation's top military officer cautioned that the United States faces decades of fighting in the larger global war on terror.

"We can vote to fight it in one place or another," said Gen. Peter Pace, whose term as chairman of the Joint Chiefs of Staff is nearing an end.

"But the bottom line is that as long as our enemy is sworn to destroy our way of life, we are going to be in a war," said Pace, addressing troops in Afghanistan.