U.S. Congressional officials say the White House intends to seek $40 billion in emergency funds to finance the next phase of recovery from Hurricane Katrina.

President Bush has already signed a $10.5 billion emergency package for hurricane victims. But one U.S. lawmaker, Senate Democratic leader Harry Reid, says the hurricane could cost the federal government $150 billion.

Earlier, Mr. Bush said he plans to oversee an investigation into what went wrong with the government's response to Hurricane Katrina.

His administration has come under heavy criticism over the government's relief efforts following the powerful storm.

Federal Emergency Management Agency Chief Michael Brown has also been the focus of widespread criticism.

Some U.S. lawmakers have called for his removal, but the White House has rejected calls for top federal emergency officials to be replaced.