The US Defence Secretary, Donald Rumsfeld, has insisted that the United States is not losing the war in Iraq.
Mr Rumsfeld told the Senate Committee on Armed Services on Capitol Hill in Washington that it would be a mistake to set a timetable for US troops to leave Iraq.
However, the senior US commander in the Middle East, General John Abizaid, said that the insurgents' strength had not diminished.
General Abizaid added that more foreign fighters were coming into Iraq than six months ago.
The Democratic Senator, Ted Kennedy, refused to accept Mr Rumsfeld's positive account.
Senator Kennedy called on the Defence Secretary to accept personal responsibility and step down.
Mr Rumsfeld said that his continuation in office was a matter for the US President, George W Bush.
