The US state of Hawaii is bracing for a dangerous category four hurricane which could hit the islands as early as Wednesday evening.

Lane was downgraded to a category four storm, with sustained winds of 155 mph (249km/h), but officials say it is still close to category five strength.

Forecasts say the islands will face strong winds and surging waves even if the storm does not make landfall.

The last category five storm to come this close to Hawaii was John in 1994.

The National Weather Service (NWS) has issued a hurricane warning for the Big Island and a hurricane watch for the islands of Oahu, Maui, Molokai and Lanai as of Wednesday morning.

On the Big Island, the first in Hurricane Lane’s path, damaging tropical storm and hurricane-force winds could pick up as soon as Wednesday afternoon or evening.

President Donald Trump urged those in the path of the storm to prepare and listen to local officials.