Death toll from Helene that tore through southeast US tops 200

More than 210 people are now confirmed dead after Hurricane Helene carved a path of destruction through several US states, officials said, making it the second deadliest storm to hit the US mainland in more than half a century.

US President Joe Biden made his second straight day of visits to the country's southeast on Thursday to grieve with residents of a region traumatised by a disaster that has upended life for millions.

The storm flooded towns and cities, made countless roads impassable, knocked out power and water service, and left communities shell-shocked as they grapple with the start of a years-long recovery effort.

A compilation of official figures by AFP confirms 212 fatalities across North and South Carolina, Georgia, Florida, Tennessee and Virginia.

More than half of the deaths were in flood-ravaged North Carolina, which is experiencing an unprecedented disaster described by some as post-apocalyptic.

"I see you, I hear you, I grieve with you — and I promise you, we have your back," Biden said during a stop at a damaged pecan farm in Ray City, Georgia.

Helene is the deadliest hurricane to hit the US mainland since 2005's Katrina, which killed 1,392 people.

Despite hundreds of rescues across six states and an enormous response including thousands of federal personnel and thousands more National Guard members and active-duty troops assisting local responders, the death toll from the sprawling storm is expected to rise.

Many residents are still unaccounted for in a mountainous region known for its pockets of isolation.

Climate crisis

Biden traveled on Thursday to Florida's northern Gulf Coast, where Helene roared ashore last week as a powerful Category 4 hurricane with wind speeds of 225 kilometres per hour.

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

Researchers say climate crisis likely plays a role in the rapid intensification of storms, because there is more energy in a warmer ocean for them to feed on.

Former president Donald Trump, who is running neck-and-neck against Vice President Kamala Harris in the November election, meanwhile lashed out Thursday with falsehoods about Washington's storm response.

"People are dying all over and they're getting no help from our federal government," Trump said in a campaign speech in Michigan, suggesting that the Biden-Harris administration has no federal funds to help storm-battered states "because they spent it all on illegal migrants."

The Sierra Club said Helene fed off record warm water temperatures in the Gulf of Mexico, supercharging the storm's power.

"Make no mistake: the unimaginable devastation we're seeing across the Southeast is the climate crisis in action," warned executive director Ben Jealous.