The US Congress's new Democratic leaders warned President George W Bush that surging more troops into Iraq would fail and it was time to end the war, days before his expected unveiling of a new US strategy.
New Senate Majority Leader Harry Reid and new House of Representatives Speaker Nancy Pelosi flexed political muscles acquired by grabbing control of Congress in November's elections, cranking up pressure on the White House.
Bush, widely expected to send more troops into Iraq in a last-ditch effort to rescue the violence-wracked nation, also faced new pressure from the opposite political flank, as hawkish senators John McCain and Joseph Lieberman urged him not to admit defeat.
Pelosi and Reid called on Bush to start a phased redeployment of US forces within four to six months.
"After nearly four years of combat, tens of thousands of US casualties and over $300 billion, it is time to bring the war to a close," the two leaders wrote.
"The American people demonstrated in the November elections that they do not believe your current Iraq policy will lead to success and that we need a change of direction for the sake of our troops," the letter said.
"Surging forces is a strategy that you have already tried and that has already failed."
"Adding more combat troops will only endanger more Americans and stretch our military to the breaking point for no strategic gain... We are well past the point of more troops for Iraq."
McCain and Lieberman, however, warned that slowly withdrawing US troops from Iraq would deal the US military, and Iraq, an unnecessary defeat.