However, U.S. military spokesman Major General William Caldwell said the fighting did not meet the U.S. military's definition of civil war.
The general's comments come amid a recent upsurge in sectarian fighting that has led some to say Iraq is already in a state of civil war and prompted Iraq's parliament on November 28 to vote unanimously to extend a state of emergency in the country for another 30 days.
UN Secretary-General Kofi Annan on November 27 became the latest person to warn that Iraq is almost in a state of civil war. He said urgent steps need to be taken to avoid civil war.
The White House said afterward that sectarian violence in Iraq had entered "a new phase." But State Department spokesman Sean McCormack said it did not amount to civil war.
"We're concerned about the level of sectarian violence and other types of violence that are ongoing in Iraq," McCormack said. "I know that there's been a lot of talk about Iraq and civil war, especially today. It's not our view and, more importantly, it's not the view of [Iraqi] Prime Minister [Nuri] al-Maliki. And I think that he would be in the best position to judge such things that are occurring on the ground in Iraq rather than us sitting here in New York or Washington."
In Tehran, Iranian President Mahmud Ahmadinejad said during a visit by his Iraqi counterpart that Iran would do what it could to help stabilize Iraq.
(compiled from agency reports)