BAGHDAD, Iraq (CNN) — Two senators are asking congressional investigators to look at Iraq's oil revenues and see if the war-ravaged nation can pay for its own reconstruction, an effort that has been bankrolled to this point mostly by U.S. taxpayers.

Carl Levin, D-Michigan, and John Warner, R-Virginia, said in their Friday letter to the Government Accountability Office that Iraq has "tremendous resources" in banks worldwide but is doing little to improve security and reconstruction efforts.

Iraqi officials did not immediately respond to the senators' allegations.