The IEDs -- homemade bombs hidden in bodies, cars or garbage and even encased in cement -- have been responsible for about half the U.S. casualties in Iraq.

"There is no shortage of funding to the effort," said Lt. Gen. James Conway at a Pentagon news conference. "There's no shortage of emphasis coming out of theater that encourages us to come to a solution. And it has been discussed, at least -- a decision has not been made, but it has been discussed that perhaps adding a three-star oversight to the effort might further enhance its ability to get things done."

Conway said U.S. efforts to thwart the IEDs have reduced their effectiveness, even though they have become more sophisticated. Techniques include jamming radio frequencies used to set off bombs by remote control.