The search for survivors has continued amid the devastation from Hurricane Helene, which has killed at least 162 people and destroyed homes across the Southeast.
Many people also remain unaccounted for, especially in North Carolina, where hundreds of roads remain inaccessible and communications have been knocked out.
The death toll rose after North Carolina's Buncombe County reported 57 dead on Tuesday, up from 40 a day earlier.
The mountainous area including the county seat of Asheville bore the brunt of the storm, which U.S. Homeland Security Secretary Alejandro Mayorkas said was of "historic magnitude."
Recovery will involve a "multibillion-dollar undertaking" lasting years, Mayorkas said.
President Joe Biden vowed to "jumpstart this recovery process" after speaking with governors and other leaders in the impacted areas.
"People are scared to death. People wonder whether they're going to make it. We still haven't heard from a whole lot of people. This is urgent," Biden said.
Hundreds of people have been reported missing, a number that is expected to decline as more telecommunications come back on line and emergency workers are able to get into remote areas.
The North Carolina National Guard has rescued over 500 people, deploying helicopters to ferry in supplies and rescue workers, rescuing survivors and pets along the way, Major General Todd Hunt told a separate press briefing.
Among the victims in North Carolina's McDowell County was David Carver, 58, who had attempted to divert water away from his home in Linville Falls, according to a friend who tried to save him.
As Carver worked with a shovel in driving rain on Friday, half his house gave way in a mudslide, taking him down the hillside with it.