Hurricane Sandy is approaching the U.S. east coast, with winds of 140 kilometers per hour, threatening massive flooding and prompting the evacuation of hundreds of thousands of people.
U.S. President Barack Obama has appeared on national television urging people in the storm's projected path to pay close attention to warnings from their local authorities and be prepared to leave their areas quickly, if requested to do so.
"The most important message that I have for the public right now is please listen to what your state and local officials are saying," Obama said. "When they tell you to evacuate you need to evacuate. Do not delay, don't pause, don't question the instructions that are being given because this is a serious storm and it could potentially have fatal consequences if people haven't acted quickly."
The storm is expected to come ashore late on October 29 or early on October 30, most likely in New Jersey.
Floods and power cuts could affect at least 50 million people.
Sandy is expected to combine with two winter weather systems which could cause snowfalls of up to one meter high.
PHOTO GALLERY: Hurricane Sandy's Landfall
A state of emergency has been declared from North Carolina to Connecticut.
Public transportation is suspended in New York City and Washington.
The U.S. stock market will remain closed on October 30.
Two of the tunnels connecting Manhattan to New Jersey and the Holland and Battery New York City boroughs were ordered to close due to fears of flooding.
President Obama warned the consequences of the storm could last for several days after the hurricane itself has passed.
"Probably the most significant impact for a lot of people in addition to flooding is going to be getting power back on," he said. "We anticipate that there are going to be a lot of trees down, a lot of water."
Sandy has already killed more than 60 people after sweeping through the Caribbean.
Thousands of domestic and international flights in and out of the eastern United States have been canceled.
With reporting by AP and AFP