Evacuation of hundreds of thousands of people was underway Wednesday in Florida and South Carolina as Hurricane Matthew approached the US coastline after leaving a path of destruction across Haiti, a report said.

Tropical storm conditions are expected to reach parts of the Florida coast by early Thursday, intensifying to hurricane conditions in some areas later that day, reported the USA Today, citing a warning issued by the National Hurricane Center.

Matthew had top sustained winds of 120 mph, a Category 3 hurricane on the Saffir-Simpson scale, Wednesday evening and is forecast to strengthen in coming days, the center said.

"People have less than 24 hours to prepare," Florida Governor Rick Scott was quoted as saying in the report. "Having a plan could be the difference between life and death."