The scale of devastation left by Hurricane Irma was far greater than anyone expected, Donald Trump has said.

Millions of people are still without power and more than 180,000 are now staying in shelters in Florida after the storm swept through the state on its way to Georgia and South Carolina.

In Jacksonville, Irma brought some of the worst flooding the city has ever seen, with more than 350 people rescued by emergency workers on Monday.

And in the south of the state displaced residents from parts of the Florida Keys are only beginning to be allowed to return home after Irma blocked a major route and cut power, water and communication lines.

Commenting on the scale of the disaster, Mr Trump tweeted: "The devastation left by Hurricane Irma was far greater, at least in certain locations, than anyone thought - but amazing people working hard!"