Hurricane Matthew is said to have devastated parts of the country, where at least two people have died.
The storm has now moved off the north-eastern coast of Cuba towards Florida, where warnings are in place.
South Carolina is to start evacuating more than a million people.
Matthew, now a category three hurricane, is predicted to hit the US east coast later in the week.
The hurricane also hit Cuba, but early reports suggested it is impact was not as hard as in Haiti, where there were winds of 230km/h (145mph), heavy rain and dangerous storm surges.