A major winter storm has brought heavy snow and ice to parts of the US and Canada, putting more than 80 million people under weather warnings.

More than 145,000 people are without power in some south-eastern states, and thousands of flights are cancelled.

Virginia, Georgia, and North and South Carolina have all declared states of emergency.

The US National Weather Service (NWS) says more than 1ft (30cm) of snow is expected in some areas.

Snow and ice could result in "dangerous travel, power outages, and tree damage", the NWS warned.

Highway patrols reported hundreds of vehicle accidents, according to the Associated Press news agency.