The Pentagon airlifted specialists and trucks from California to New York to help restore power to millions of people in America's storm-hit north-eastern states.
About 4.5 million homes and businesses in 12 states remained without power on Thursday in the wake of super-storm Sandy that pummelled the the east coast.
The C-5 and C-17 military transport planes, designed to carry heavy military equipment, began flying from a southern California base early on Thursday.
More than 100 employees of Southern California Edison, one of southern California's biggest power companies, were flying out on the military flights and a separate charter flight, Reuters reported.
Forecasters say the storm could cost the country $US50 billion, doubling the previous estimate.
Death toll rises
By Thursday, the death toll from the super-storm had risen to 98, including 40 fatalities in New York City, and others are missing.
More deaths had been recorded in the New York City borough of Staten Island, where authorities recovered 17 bodies after the storm lifted whole houses off their foundations.
In New Jersey, 20,000 people remained trapped in their homes by sewage-contaminated floodwater.
Entire neighbourhoods in oceanside New Jersey towns were swallowed by sea water and the Atlantic City boardwalk was destroyed.
Sandy made landfall in New Jersey on Monday evening with a full moon around high tide, creating a record storm surge that flooded lower Manhattan. By Thursday, the storm had dissipated over the North American mainland.
In the Caribbean, Hurricane Sandy killed 69 people.
Fuel supply disruption hinders recovery
Power cuts are contributing to growing problems getting petrol stations back open, and taxi and car service companies in New York have started pulling vehicles off the road because they can't refuel.
As many as three-quarters of the city's petrol stations may be closed, either because they have run out of fuel or have no electricity to pump it.
Two refineries that supply a quarter of New York and New Jersey's petrol and diesel are out of action because of power cuts or flooding.
The first subway trains began moving in New York as floodwaters from huge sea surges was slowly cleared from tunnels.
The National Guard was delivering 1 million meals and bottled water to New Yorkers affected by the storm.
Obama, Romney resume campaign
President Barack Obama and Republican Mitt Romney resumed the election campaign suspended during the storm.
National polls show the race is essentially deadlocked, Reuters reports.
Mr Obama and Mr Romney will spend the final days in eight swing states that will decide who wins the 270 electoral votes needed to capture the White House.