WASHINGTON - Federal Emergency Management Agency Director Michael Brown, the principal target of harsh criticism of the Bush administration's response to Hurricane Katrina, was relieved of his onsite command Friday.

He will be replaced by Coast Guard Vice Adm. Thad W. Allen, who was overseeing New Orleans relief, recovery and rescue efforts, Homeland Security Secretary Michael Chertoff announced.

Earlier, Brown confirmed the switch. Asked if he was being made a scapegoat for a federal relief effort that has drawn widespread and sharp criticism, Brown told The Associated Press after a long pause: "By the press, yes. By the president, no."

"Michael Brown has done everything he possibly could to coordinate the federal response to this unprecedented challenge," Chertoff told reporters in Baton Rouge, La. Chertoff sidestepped a question on whether the move was the first step toward Brown's leaving FEMA.

But a source close to Brown, speaking on condition of anonymity, said the FEMA director had been considering leaving after the hurricane season ended in November and that Friday's action virtually assures his departure.

Brown has been under fire and facing calls for his resignation because of the administration's slow response to the magnitude of the hurricane. On Thursday, questions were raised about whether he padded his resume to exaggerate his previous emergency management background.