A compilation of official figures by AFP confirms 201 fatalities across North and South Carolina, Georgia, Florida, Tennessee and Virginia. More than half of the deaths were in flood-ravaged North Carolina.

Helene is the deadliest on the US mainland since 2005's Hurricane Katrina, which killed 1,392 people.

Despite hundreds of rescues across six states and an enormous response including more than 10,000 federal personnel assisting local responders, the death toll from the sprawling storm is expected to rise, with many residents still unaccounted for in a mountainous region known for its pockets of isolation.

"We are continuing to find survivors," North Carolina's Buncombe County, the epicenter of the tragedy where more than 60 people are confirmed dead, said in its latest update, adding there are residents still cut off from the outside world due to landslides and destroyed bridges.

"Our thoughts and prayers continue to go out to the families of those that had just experienced this heartbreak and this tragedy," Georgia Governor Brian Kemp told a briefing n his state, where he said the number of confirmed dead has risen to 33.

US President Joe Biden was undertaking a second straight day of visits to affected states, traveling Thursday to Florida, where Helene blew into the state's northern Gulf shore last week as a powerful Category 4 hurricane with wind speeds of 140 miles (225 kilometers) per hour.

Biden took an aerial tour of the coast to survey the devastation, then walked past rows of destroyed homes and buildings in Keaton Beach, near where the storm made landfall.

He next heads to neighboring Georgia.