The White House is expected to ask the U.S. Congress for about $18 billion in new emergency funds for the hurricane-battered Gulf coast, a Senate aide told Reuters on Thursday. Donald Powell, the coordinator for the federal government's Gulf coast rebuilding effort, is expected to make the announcement later in the day. Congressional staffers were being briefed on the funding request, which is in addition to $62 billion that Congress approved last year following the devastation of Hurricanes Katrina and Rita.