Michael Brown, head of the Federal Emergency Management Agency in charge of the U.S. response to natural disasters, resigned Monday just three days after losing his onsite command of the Hurricane Katrina relief effort.

Former chief of the Miami-Dade Fire Rescue Department R. David Paulison was nominated by President Bush to head the Federal Emergency Management Agency.

Brown, under fire for FEMA's performance in the Gulf Coast, said he feared he had become a distraction.

"The focus has got to be on FEMA, what the people are trying to do down there," Brown said.

His decision was not a surprise. Brown was abruptly recalled to Washington on Friday, a clear vote of no confidence from his superiors at the White House and the Homeland Security Department.

Brown had been roundly criticized for FEMA's sluggish response to the hurricane, which has caused political problems for Bush and fellow Republicans. He also was accused of padding his resume, which Brown denied Friday.

Bush, touring Gulfport, Miss., refused to comment on the resignation, saying he had not had a chance to talk to Brown or Brown's immediate boss, Michael Chertoff, secretary of the Department of Homeland Security.

Bush plans to go to New York tomorrow in advance of his speech Wednesday to the United Nations and will meet with a number of foreign leaders. Asked if he was ready to switch to foreign policy issues from the hurricane, he said, "I can do more than one thing at one time."