Power is slowly being restored in New York after Superstorm Sandy crippled the energy supply for millions in the northeast United States, but a fuel shortage persists in the region.

As of Saturday afternoon, about 60 per cent of the New York metropolitan area had power restored, but there were still about 900,000 people without electricity, according to New York Gov. Andrew Cuomo.

With many people without power relying on generators, a lack of gas has caused frustration.

To alleviate the pressure, New Yorkers will be able to obtain free gas at emergency mobile gas stations in five locations throughout the metropolitan area, but rations will be limited to 38 litres per person.

The situation was similar in New Jersey, where “some people have been standing in lines for hours just to get a gallon of gas, only to learn that by the time they get to the front of the line that that station has run out of gas,” ABC News’ Alex Perez told CTV News Channel.

By Saturday morning, an executive order signed by New Jersey Gov. Chris Christie came into effect in the 12 hardest-hit counties, where drivers will be able to fill up every other day depending on their license plates -- those that end with even numbers can get gas on even-numbered days, while those ending in odd numbers are limited to odd-numbered days, Perez said.

The Federal Emergency Management Agency and the military were also set to clear the way so that 22 million gallons of fuel can be delivered to the region, where many roads were damaged by the storm.

It could take until the end of next week for normalcy to resume, according to Perez, and locals are stocking up on water and other necessities as a contingency.

In Washington, during a visit to FEMA headquarters, U.S. President Barack Obama stressed the importance of dealing with the crisis properly.

"Obviously we've now seen that after the initial search and rescue, the recovery process is difficult and it's painful," Obama said. "But I'm confident that we will continue to make progress as long as state and local and federal officials stay focused."

The post-tropical storm left 106 dead in the U.S., including 40 in New York City.

Power outages affected more than 6 million residences and businesses nationwide. More than 2.6 million people remain without power in several states.

By Friday, mounting pressure forced New York Mayor Michael Bloomberg to cancel the annual New York City Marathon after New Yorkers questioned the logic of allocating power supplies for the marathon while residents were still without electricity.

With an estimated $50 billion in damage, Sandy is the second costliest Atlantic hurricane to affect the United States, after 2005’s Hurricane Katrina.

With files from The Associated Press