A historic winter storm has placed 54 million people under blizzard warnings and prompted travel restrictions in multiple areas, including a travel ban New York City.

States of emergency have been declared in states including Connecticut, Delaware, New Jersey and Rhode Island, with restrictions on travel. New York, Connecticut and Massachusetts have similar orders in place as the storm approaches the coast.

Other parts of US northeast and the Canadian Maritimes are also expected to be walloped on Sunday and Monday, forecasters say.

It's expected to be the most powerful nor'easter storm in nearly a decade for many parts of the northeast, bringing snow, fierce winds and coastal flooding.

About 35mn people are impacted by the blizzard warning, and another 19mn are are under winter storm warnings, which covers the Central Appalachians to coastal Maine.