The US Democratic Party's congressional spokesperson on defence has called for an immediate withdrawal of US troops from Iraq.
"The US cannot accomplish anything further in Iraq militarily. It is time to bring them home," said Rep. John Murtha of Pennsylvania, the senior Democrat on the House of Representatives subcommittee that oversees defence spending and one of his party's top voices on military issues.
His remarks followed a string of sharp attacks by President Bush and Vice President Dick Cheney against critics of their Iraq-war policy and handling of prewar intelligence.
White House spokesman Scott McClellan, in a statement issued with Mr Bush in Pusan, South Korea, said Mr Murtha is a respected veteran and politician "so it is baffling that he is endorsing the policy positions of Michael Moore and the extreme liberal wing of the Democratic Party".
His call came two days after the Republican-controlled Senate overwhelmingly backed a resolution asking the administration for a plan to end the war but rejected a Democratic resolution demanding a timetable from the president.
Mr Murtha, who supported the Iraq war but criticised Mr Bush's handling of it, urged the administration to pull out US troops as soon as it could be done safely. He estimated that would take about six months.
Republicans condemned the lawmaker who has served in Congress since 1974 and been a trusted defence adviser to presidents of both parties.
House Speaker Dennis Hastert, an Illinois Republican, said Mr Murtha and other critics "want us to wave the white flag of surrender to the terrorists of the world. . . . We must not cower like European nations who are now fighting terrorists on their soil."