President Barack obama today declared emergency in three States of New York, Virginia and Massachusetts which empowered federal agencies to take all steps required to protect people and properties, as hurricane Irene with a sustained wind speed of 100 miles per hour gushed toward the eastern shores of the United States.

While Obama declared emergency in New York early in the day, the US President signed off on the emergency declaration for the States of Virginia and Massachusetts around midnight soon after he arrived at the White House, a day early from his summer vacation.

Emergency in North Carolina was declared earlier. Obama's action authorizes the Department of Homeland Security, Federal Emergency Management Agency, to coordinate all disaster relief efforts which have the purpose of alleviating the hardship and suffering caused by the emergency on the local population, and to provide appropriate assistance for required emergency measures, to save lives and to protect property and public health and safety, and to lessen or avert the threat of a catastrophe in these three States.

Governors of Florida, North Carolina, Virginia, Maryland, Delaware, New Jersey, Connecticut, and New York have already declared states of emergency as hurricane Irene nears land.

Federal storm-surge maps showed the potential for four-to 10-foot surges across a massive swath of the eastern United States, with potentially disastrous impacts in eastern North Carolina, the Tidewater area of Virginia, as well as the Potomac River that runs through Washington.

"Hurricane Irene lashed coastal North Carolina late Friday and had metropolitan New York in its sights, staying on an unusual track that could bring deadly storm surge, heavy rainfall and misery to millions," CNN reported from North Carolina.

It was expected to hit Virginia, Maryland and Washington on Saturday night.

Meanwhile, tens and thousands of people across the east coast were evacuated from the low-lying areas.

"The storm was on a track that experts have feared for decades as they watched the rapid expansion of coastal resorts and housing developments in the lowlands behind them. They have worried that a storm tracking along the shore line, renewing its force over the warm Atlantic and then ripping with each rotation like a circular saw into coastal areas, could produce unprecedented devastation," The Washington Post said.

"It looks like the track of Irene is going to have a major impact along the East Coast starting in the Carolinas all the way up through Maine," said Craig Fugate, director of the Federal Emergency Management Agency.