President George W Bush has declared four Florida counties disaster areas, after storms and a tornado killed at least 20 people in the US state.
Some 1,500 houses were damaged by the storms
Mr Bush's move frees federal aid for recovery operations in Florida to supplement local efforts.
Rescuers have completed their search for survivors, and damage assessment teams are investigating the scene.
The storms hit before dawn on Friday, damaging some 1,500 houses and leaving more than 10,000 people without power.
All the deaths occurred in the central Lake County, where some of the worst of the damage was reported.
"I just received a call from the White House that the president has signed the declaration for public assistance," David Paulison, the director of the Federal Emergency Management Agency (Fema) said.
He said Fema trucks were on their way with food, water and other supplies, but urged volunteers to help with recovery operations.
"It's neighbours helping neighbours. If we work together, we can do this," Mr Paulison said.
Shelters have been opened to house the affected residents.
Some residents returned to pick through the rubble of their homes and salvage their belongings, helped by National Guard troops and jail inmates.
Earlier, rescue teams combed through piles of debris in search for survivors and bodies.
Officials said it could take several days to determine the exact number of dead.
'Like a train'
The storms hit during the night, at about 0315 (0815 GMT), when most residents were sleeping.
Residents likened the storms to a freight train that hit their homes.
Hilary Hague, who lives in The Villages retirement complex near Lady Lake, told BBC News that the storms had started with severe lightning, followed by heavy rain.
She said it got worse later " when there was almost continuous lightning".
She said survivors were "quite shocked - this is not a usual occurrence in this area - but also grateful" that they had apparently escaped the deaths and injuries suffered elsewhere.
In 1998, tornadoes killed 42 people in Florida in what was the state's worst storm on record.
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