General David Petraeus, the top US military commander in Iraq, has hinted he will recommend a reduction in US troop numbers around March when he reports to congress next week.
"The surge will run its course. There are limits to what our military can provide, so, my recommendations have to be informed by - not driven by - but they have to be informed by the strain we have put on our military services," Petraeus said.
"That has to be a key factor in what I will recommend," he told ABC News in an interview at Camp Victory in Baghdad broadcast late on Tuesday.
Petraeus declined to be specific about the recommendations, which he gave to George Bush during the US president's surprise visit to Iraq on Monday.
Attacks 'reducing'
But when asked if a reduction to avoid further strain on the military could happen in March, he replied: "Your calculations are about right."
ABC News quoted him as saying he is not feeling pressure from the political debate to present a "rosy picture" of the war.
He said: "This is not Ambassador Crocker and General Petraeus, who will decide what is to be done about Iraq.
"This will be a decision made at two ends of Pennsylvania Avenue."
While admitting it was still very dangerous in Iraq, Petraeus said the so-called "surge" in US troops had produced an "initiative, in general, against al-Qaeda, which is a change, and that is an important change".
"Eight of the past 11 weeks have seen the number of incidents, the number of attacks, come down, and to the point that they reached a level that's about the lowest in well over a year, I think," he said.
Baghdad blast
The US military also announced that four soldiers have been killed in separate attacks in Baghdad.
Three soldiers were killed and two wounded by a blast that hit their patrol on Tuesday, the military said.
Another soldier was killed and two more wounded during combat operations in a western Baghdad area.