By Nick Childs
BBC correspondent, the Pentagon
The top US commander in the Iraq conflict, General Tommy Franks, says he does not know how many troops will have to stay in Iraq or for how long.
US troops are having to deal with mounting Iraqi frustration
Appearing at a Pentagon news conference, General Franks insisted, though, that the situation in the country was improving.
General Franks is in Washington for the first time since the start of the Iraq conflict to brief President George W Bush, other top US officials and Congress on operations there.
And in his first news conference appearance since early in the conflict, the man who commanded US-led forces insisted that the United States is committed to staying to help Iraq rebuild.
"We are going to watch this nation form anew, in accordance with what the Iraqi people themselves want to do, and I'm not sure at this point that we know exactly what the force, structure or size is going to look - or what the international content is going to look like as we move forward," General Franks said.
The US Defence Secretary, Donald Rumsfeld, who was appearing with General Franks, also said it was "not knowable", as he put it, how long US-led forces would have to stay.
Both men rejected criticism of US efforts so far to stabilise Iraq, and painted a picture of steady improvements across the country.
After much early criticism of the US war plan, General Franks insisted it was a good plan and that its execution by US and coalition forces was "magnificent".