From Sunday through Monday noon, Obama has declared a state of emergency for Maryland, Massachusetts, New Jersey, Connecticut, Pennsylvania, Rhode Island and Delaware where Hurricane Sandy could cause severe damage, making federal aid available for local response and rescue.

U.S. federal offices would be closed to the public Tuesday, with only emergency employees required to work, the U.S. Office of Personnel Management said.

Sandy, which has killed 69 people in the Caribbean, will meet up with cold fronts coming out of the northwest and a high pressure system from Greenland, fueling it with enough energy to be as powerful as, or even worse than the 1991 storm.

The combination superstorm could impact about 50 million people cutting in it path.

As the storm approaches, the East Coast is bracing for a repeat of the "perfect storm" of 1991, which came around Halloween that year and killed dozens of people.

Meteorologists have been using the term "Frankenstorm" to describe the havoc. Sandy, expected to make a landfall around Halloween, could affect hundreds of millions of people living along the East Coast.