World Bulletin / News Desk

US President Barack Obama on Friday declared a federal state of emergency in Florida as Hurricane Matthew's powerful winds began to be felt along the state's southeast coast.

He ordered federal aid to supplement state and local efforts to deal with the devastating storm, authorizing the Homeland Security Department and the Federal Emergency Management Agency (FEMA), to coordinate disaster relief efforts.

More than 2 million people are expected to flee homes across the southeastern U.S. as Hurricane Matthew barrels toward the country on Thursday.

Recently upgraded to a Category 4 storm with sustained winds reaching 140 mph (225 kph), Matthew could be one of the worst storms to batter the U.S. in the past decade.

The last major hurricane, measured as a Category 3 or higher, was Wilma in 2005. 

The storm has left a trail of devastation in the Caribbean. Haiti has been particularly hard hit with officials warning that the death toll there has already exceeded 100 victims and will likely rise. 

In the U.S., evacuations are underway in Florida, Georgia and South Carolina. 

The White House urged Americans to take the approaching storm seriously, pointing to the widespread damage it has already inflicted. 

"If there are those who doubt the intensity or severity of the storm, they need only look at the images that are coming back from Haiti," spokesman Josh Earnest told reporters. 

"That is pretty good evidence of what people in the southeast could be facing," he added. 

Florida Gov. Rick Scott strongly warned residents to follow evacuation orders. 

"Do not surf. Do not go on the beach. This will kill you," he said at a news conference early Thursday. "Evacuate, evacuate, evacuate."

More than 3,000 people have already taken shelter at 60 centers across Florida, he said. 

The Gulf Coast Hurricane Center warned that Matthew is likely to have "devastating impacts", and that "evacuations are not just a coastal event."

The center added that residents of mobile homes should heed evacuations orders because "strong winds will occur well inland from the coast". 

The storm could make landfall in eastern Florida somewhere around West Palm Beach early Friday. Even if it skirts the coast, it could still wreak major havoc across the southeastern seaboard.

Matthew may reach South Carolina or Georgia as early as Saturday morning.