Hurricane Florence could be upgraded to a Category 5 storm, the highest level, as it threatens to bring mass devastation to the US
east coast.
In an urgent warning,
USA weather forecasters said Hurricane Florence would grow stronger and larger before making landfall early on Friday.
The storm, currently a Category 4, is hurtling towards the coast of North and South Carolina and Virginia with sustained winds of 140mph (225 km/ph).
More than one million residents have been forced to flee the east coast amid fears Florence will spark torrential rain and catastrophic floods.
The hurricane's centre is most likely to strike the southern coast of North Caroline, according to maps of Florence's trajectory.
The US National Hurricane Centre (NHC) warned that tropical storm-force winds could extend nearly 300 miles across the three states.
North Carolina Governor Roy Cooper urged residents to follow evacuation warnings, saying: "This storm is a monster, it's big and it's vicious.
"The waves and the wind this storm may bring is nothing like you've ever seen.
"Even if you've ridden out storms before, this one is different. Don't bet your life on riding out a monster."
Donald Trump yesterday declared states of emergency for North and South Carolina and Virginia, paving the way for federal aid.
The US president told reporters at the White House: "We are sparing no expense, we are totally prepared.
"We are as ready as anybody has ever been. The safety of the American people is my absolute highest priority.
"This is going to be a very large one. It's tremendously big and tremendously wet. Tremendous amounts of water."
NHC director Ken Graham said he was "really scared" about the potential devastation Hurricane Florence could bring.
Speaking yesterday, he said: "You're going to get heavy rain, catastrophic life-threatening storm surge and also the winds.
"The water could overtake some of these barrier islands and keep on going.
"With time, the wind pushes the water into every nook and cranny you can think of.
"All you have to do is look up at your ceiling and think about 12ft of water. That, folks, is extremely life-threatening."