The U.S. National Weather Service has once again labelled a massive storm heading north toward the Eastern United States and Canada from the Bahamas a hurricane, after briefly downgrading it to a tropical storm.

Forecasters on Saturday said Sandy was churning with sustained winds of 120 km/hr. Earlier in the day, the reported wind speed had dropped to below 110 km/hr as the storm was 565 kilometres south-southeast of Charleston, S.C., or 250 kilometres north of Great Abaco Island in the Bahamas.

The National Weather Service has warned that "widespread impacts" from Sandy are expected into next week for the U.S. East Coast.

The storm was expected to increase in speed and move away from the Bahamas and parallel to the southeast coast of the United States later this weekend.

The effects of Sandy are likely to be felt north of the border late Monday, heading into Tuesday and Wednesday, with strong winds expected in much of the Maritimes, as well as southern Quebec and southern Ontario.

Susan McGinnis with CBS News reported from Rehoboth Beach in Delaware, where people are boarding up their homes and stocking up on food and water.

"This is one of the possible targets for Sandy to make that left turn and then to hit the United States, then on its move westward, where it's likely to join up with that wintry storm system and cause this 'superstorm' that we've been hearing about," McGinnis told CBC News.

Sandy killed more than 40 people as it swept over the Caribbean, wrecking homes and knocking down trees and power lines.

The storm is expected to make landfall early Tuesday near the Delaware coast, then hit two winter weather systems as it moves inland, creating a hybrid monster storm that could bring a heavy deluge of rain and high winds.

Forecasters say the storm could cause major travel disruptions all along the U.S. Eastern Seaboard.

Presidential rivals Mitt Romney and Barack Obama have both cancelled weekend rallies in Virginia, where officials are bracing for power outages and other storm damage. Utilities throughout the region are securing extra crews and equipment.

Environment Canada says the storm will lose strength as it turns inland. With files from The Associated Press