Major General William Caldwell also says Iraqi and U.S.-led coalition troops are expecting violence to increase further during the Muslim holy month of Ramadan.
Caldwell says the attacks against U.S. troops were mostly carried out by suicide car bombers or car bombs.Meanwhile, a UN report says at least 6,599 civilians died in Iraq over July and August, or nearly 800 more than in the previous two months.
The report said the July total of 3,590 deaths was unprecedented, while the August figure, though lower, was also among the worst yet.
It said that "hundreds of bodies" bearing signs of torture and execution-style killings continued to appear throughout the country.
(Reuters, AFP, AP)