The White House is prepared to keep as many as 10,000 U.S. troops in Iraq after the end of the year, amid growing concern that the planned pullout of virtually all remaining American forces would lead to intensified militant attacks, according to U.S. officials.

Keeping troops in Iraq after the deadline for their departure at the end of December would require agreement of Iraq's deeply divided government, which is far from certain. The Iraqis so far have not made a formal request for U.S. troops to remain, according to the officials,