Fuel supplies headed toward disaster zones in the US northeast and a million customers regained electricity ahead of a coming cold snap that threatened to add to the misery of coastal communities devastated by superstorm Sandy.

The power restorations relit the skyline in lower Manhattan for the first time in nearly a week and allowed 80% of the New York City subway service to resume.

However 2.5 million homes and businesses still lacked power, down from 3.5 million yesterday.

The power outages combined with a heating oil shortage meant some homes could go cold as wintry weather sets in.

Forecasters saw temperatures dipping to around 3oC, with similar low temperatures expected next week.

"There's no heating oil around," said Vincent Savino, the president of Statewide Oil and Heating, which usually supplies some 2,000 buildings across New York City. "I don't know how much fuel we have left: maybe a day or two."

The long, arduous recovery was taxing disaster victims and first responders strained by a week of emergency services.

The storm's North American death toll rose to at least 110 with nine more deaths reported in New Jersey, raising the total in that state to 22. New York revised its total down by one to 40.

Sandy killed 69 in the Caribbean before turning north and hammering the US northeast coast with 130 kmph winds and a record surge of seawater that swallowed oceanside communities in New Jersey and New York, and flooded streets and subway tunnels in New York City.

"It's just breathtaking," said New Jersey Governor Chris Christie, who ordered rationing that allows only half of all cars to buy gasoline each day. "I was there (at the Jersey Shore) yesterday and I will tell you, it looked like we had been bombed. There are homes in Bay Head on the beach that had been driven by the storm surge into the houses across the street."

Tight gasoline supplies have tested the patience of drivers - fist fights have broken out in mile-long lines of cars - but fuel was making its way to terminals after the US Coast Guard reopened New York Harbour to tanker traffic yesterday.

Alleviating one of the country's worst fuel chain disruptions since the energy shortage in the 1970s, some 8 million gallons of gasoline and other petroleum products have been delivered since yesterday and another 28 million gallons was to be delivered this weekend, New York Governor Andrew Cuomo told a news conference.

Mr Cuomo also announced the Defence Department would set up five mobile gas stations in the metropolitan area, providing people with up to 10 gallons of free gas.