The US House of Representatives has passed a bill requiring a withdrawal of most combat troops from Iraq starting within 120 days, to be completed by April 1.

The House voted by 223 votes to 201 to pass the measure, in defiance of President George W Bush, who has already vetoed a previous troop withdrawal timeline framed by the Democratic Party, and has pledged to do so again.

Four Republicans voted in favour of the plan, while 10 members of the majority Democratic Party voted against, on a day a new US government report offered a bleak snapshot of progress in Iraq.

House Democratic leaders argued during a day-long debate on the measure that Bush's war plan had failed and it was time to change track.

"Let's change our strategy, and demand that the Iraqis step up and be responsible for their country, let's responsibly redeploy our troops," said Democratic House majority leader Steny Hoyer.

But Republicans accused their foes of backing a plan for defeat in Iraq.

House Minority leader John Boehner branded the measure a "meaningless bill that undermines our troops."

"If we fail in Iraq we know what happens, we make America less safe," he said.