Gen John Abizaid, the top US commander in the Middle East, and David Satterfield, the State Department's senior adviser on Iraq, were scheduled to testify before the House and Senate Armed Services committees on Wednesday, followed by CIA Director Gen. Michael Hayden and Defence Intelligence Agency Director Lt Gen Michael Maples.

"I would hope and expect that we're going to be given some indication at that hearing that they see the need to change direction," said Sen Carl Levin, who will take control of the Senate Armed Services Committee next year.

"My displeasure with the president, he doesn't understand the urgency of this," incoming Senate Majority Leader Harry Reid told The Washington Post. "It's all victory for him, but I don't know what that means anymore in Iraq. I do know what we are doing now doesn't work.