WASHINGTON – The White House and Homeland Security chief Michael Chertoff failed to provide decisive action when Hurricane Katrina struck, congressional investigators said yesterday in a stinging assessment of slow federal relief efforts.

The White House had no clear chain of command in place, investigators with the Government Accountability Office said, laying much of the blame on President Bush for not designating a single official to coordinate federal decision-making for the August 29 storm. Mr. Bush has accepted responsibility for the government’s halting response, but for the most part FEMA’s then-director, Michael Brown, who quit days after the hurricane hit, has been the public face of the failures.

“That’s up to the president of the United States,” the GAO comptroller general, David M. Walker, told reporters after being asked whether Mr. Chertoff should have been the lead official during the emergency.

“It could have been Secretary Chertoff” or someone on the White House staff, Mr. Walker added. “That’s up to the president.”

The report, which the congressional agency said was preliminary, also singled out Mr. Chertoff for several shortcomings. Mr. Chertoff has largely escaped direct criticism for the government’s poor preparations and slow rescue efforts.

The Homeland Security Department angrily responded to the GAO report, calling the preliminary findings a publicity stunt riddled with errors. Homeland Security oversees the Federal Emergency Management Agency and issued a national plan last year for coordinating federal disaster response with state and local agencies.

In the nine-page report, investigators noted that they had urged the Clinton White House to appoint a single disaster coordinator more than a decade ago after the destruction wrought by Hurricane Andrew. Still, they said, the Bush administration continued the failure with the lack of a clear chain of command and that led to internal confusion when Katrina struck.

“In the absence of timely and decisive action and clear leadership responsibility and accountability, there were multiple chains of command,” the report found.

The assessment – the first of several reports about the response to Katrina – noted that Mr. Chertoff authorized additional federal assistance to overwhelmed state and local resources on August 30, a day after the storm hit. But Mr. Chertoff did not specifically classify the storm as a catastrophic disaster, which would have triggered a faster response.

In another stab at Mr. Chertoff, the report called for Homeland Security to provide stronger advance training and planning for future disasters – including taking better advantage of the military’s ability to evacuate victims, provide supplies, and assess damage.