The vote on the nine-month withdrawal measure was 255-171.

On a day of complex maneuvering, Democrats said they would approve legislation funding the war on an installment plan, and Bush said he would veto it. But the president, under pressure from lawmakers in both parties, coupled his threat with an offer to accept a spending bill that sets out standards for the Iraqi government to meet.

"Time's running out, because the longer we wait the more strain we're going to put on the military," said Bush, who previously had insisted on what he termed a "clean" war funding bill.

The House challenged Bush as Iraqi Deputy Prime Minister Barham Saleh held a series of meetings with key senators, a reflection of concern on the part of the government in Baghdad that support for the war was waning in Congress.

In a brief interview with The Associated Press, Saleh said the purpose of the meeting was to convey the "imperative of success against terrorism and extremism" in the Middle East.

Despite Bush's ability to sustain his vetoes in the House ¡ª as demonstrated last week ¡ª critics of the war insisted on challenging him anew.

"This war is a terrible tragedy and it is time to bring it to an end," said Rep. James McGovern, leading advocate of the bill to establish a nine-month withdrawal timetable. "For four long, deadly years, this administration and their allies in Congress have been flat wrong about Iraq," said the Massachusetts Democrat.

Republicans argued that a withdrawal would be disastrous.

"Now is not the time to signal retreat and surrender. How could this Congress walk away from our men and women in uniform," said Rep. Jerry Lewis, R-Calif.

The bill drew the support of 169 Democrats and two Republicans. There were 59 Democrats and 196 Republicans opposed.

Bush's critics in Congress treated his willingness to apply benchmarks to the Iraqis as a concession, but said they wanted more. "Democrats are not going to give the president a blank check for a war without end," said House Speaker Nancy Pelosi of California.

To buttress her point, Democrats advanced legislation for a vote later in the evening providing funds for the war grudgingly, in two installments. The first portion would cover costs until Aug. 1 - $42.8 billion to buy equipment and train Iraqi and Afghan security forces.

Under the bill, it would take a summertime vote by Congress to free an additional $52.8 billion, the money needed to cover costs through the Sept. 30 end of the fiscal year.

"We reject that idea. It won't work," the president declared after a meeting with military leaders at the Pentagon.

Democratic officials, speaking privately, said Pelosi had agreed to allow the vote on the withdrawal measure in the hope that her rank-and-file would then unite behind the funding bill.

But in an increasingly complex political environment, even that measure was deemed to be dead on arrival in the Senate, where Democrats hold a narrow advantage and the rules give Republicans leverage to block legislation.

Senate Majority Leader Harry Reid, D-Nev., has met privately in recent days with White House Chief of Staff Josh Bolten and Senate Minority Leader Mitch McConnell, R-Ky., the beginning of talks aimed at producing a compromise funding bill that Bush would sign.

In a speech in January, Bush listed several goals for the Iraqis, including legislation to share oil revenue among all Iraqis, spending $10 billion on job-creating reconstruction projects, holding provincial elections, overhauling de-Baathification laws and creating a fair process for considering amendments to the constitution.

But in contrast to many lawmakers, the administration has not yet publicly accepted proposals to make future reconstruction funds conditional on Baghdad's progress in achieving the goals.

Bush and the Democratic leaders were maneuvering in a complicated political environment.

Republican lawmakers have grown increasingly restive about a war that they believe cost them their congressional majorities in last fall's elections. In a private meeting with Bush and several key administration officials at the White House, 11 moderate GOP lawmakers bluntly told Bush that the status quo was unsustainable and could mean further election losses next year.

Pelosi and Reid face obstacles of their own.

They are determined to make sure that essential funding for the war is not cut off. At the same time, they are laboring to keep faith with their own rank-and-file, with the war-weary voters who installed them in power, and with MoveOn.org and other groups whose overriding goal is to force the withdrawal of the U.S. combat troops.

MoveOn.org, in particular, has played a key behind-the-scenes role in the months since Congress convened under Democratic majorities. The group, which played a highly visible role in last year's election campaign, acquiesced in an early Democratic strategy of seeking approval for nonbinding measures to pressure Bush to change his plans.

In recent weeks, that has changed. Fearing that Democrats ultimately will surrender and give Bush the money he wants, the organization sent Reid and Pelosi a letter saying that if Democrats "appear to capitulate to Bush on Iraq, MoveOn will move to a position of opposition."