Hurricane Irma has caused widespread destruction across the Caribbean, reducing islands to rubble and leaving at least seven people killed.
The small island of Barbuda is said to be "barely habitable" while officials warn that the French territory of St Martin is almost destroyed.
With the scale of the damage still emerging the death toll is likely to rise, BBC reports on Thursday.
Meanwhile, two other storms have strengthened to become hurricanes.
Irma, a category five hurricane, the highest possible level, is currently passing north of the US territory of Puerto Rico, the US National Hurricane Center said.
More than half of the island's three million residents were without power as Irma caused heavy downpours and strong winds. Officials have said that power could be cut off for several days.
The most Atlantic powerful storm in a decade had wind speeds of 295km/h (185mph) and was expected to pass near or just north of the coast of the Dominican Republic on Thursday.
Hurricane Irma first hit the dual-island nation of Antigua and Barbuda. At least one death, of a child, was reported on Barbuda, where Prime Minister Gaston Browne said about 95 per cent of the buildings had suffered some damage.
"It is absolute devastation," he said after flying over the island, home to some 1,600 people. "The island is literally under water. In fact, I'm of the view that, as it stands now, Barbuda is barely habitable."
However, Antigua, population 80,000, escaped major damage, with no loss of life, he said earlier.
Officials have confirmed at least six deaths and considerable damage in the French territories of St Martin and Saint Barthélemy - the French holiday destination popularly known as St Barts.
St Martin's airport, the third largest in the Caribbean, has been destroyed, with local officials saying that most buildings on the territory have been levelled.
Residents are said to be without drinking water and electricity and emergency crews are still trying to reach the worst-hit areas.
Significant damage was also reported in the Dutch section of St Martin, known as Sint-Maarten.
US President Donald Trump said he and his aides were monitoring Irma's progress. "But it looks like it could be something that will be not good. Believe me, not good," he told reporters at the White House.
It is still not yet clear what impact Hurricane Irma might have on the US mainland but projections suggested it could hit the state of Florida on Sunday.
Officials started evacuations of tourists and residents of Florida Keys, a resort archipelago.
A state of emergency had been declared for Florida, Puerto Rico, and the US Virgin Islands, mobilising federal disaster relief efforts.
British Foreign Secretary Boris Johnson said the government was in touch with British overseas territories caught up in Irma, and was doing "everything we can to help those afflicted".
