People wade and paddle down a flooded street as Sandy approaches, Monday, Oct. 29, 2012, in Lindenhurst, N.Y. Gaining speed and power through the day, the storm knocked out electricity to more than 1 million people. (AP Photo/Jason DeCrow)

The storm headed for the east coast of the United States is no longer a hurricane, forecasters have said, but is still a dangerous system taking aim at New Jersey and Delaware.

The National Hurricane Centre said tonight that Sandy is a post-tropical storm and losing strength, but still has sustained winds at 85mph. The eye has almost made landfall.

The centre says that storm surge has reached heights of 12.4 feet at Kings Point, New York.

Gaining speed and power through the day, the storm knocked out electricity to more than 1.5 million people and forced millions more to take measures to protect themselves and their property.

From Washington to Boston, subways, buses, trains and schools were shut down and more than 7,000 flights grounded across the region of 50 million people. Hundreds of thousands of people were under orders to move to higher ground to await the storm.