North Carolina and New York state have been declared major disaster zones after being hit by Tropical Storm Irene.
The move by President Barack Obama allows the two states to access extra funds for relief efforts. He earlier signed an emergency declaration for Vermont following the storm, which caused mass travel chaos and damage estimated at more than $10 billion across the US east coast.
More than 200 roads were blocked or washed away in Vermont, hampering rescue efforts to as many as 13 towns. The National Guard was called in to provide food, water and other emergency supplies to areas cut off by the storm.
Swollen rivers along the north-eastern seaboard have begun receding after they caused extensive flooding and prompted emergency rescues in states such as New Jersey.
The storm resulted in at least 45 deaths in 13 states as it brought hurricane-force winds to North Carolina and torrential rain to New York, New Jersey, Connecticut and Vermont. At least 1.7 million homes and businesses in the affected areas are still reported to be without power.
Irene swept up the eastern seaboard after making landfall as a category one hurricane in North Carolina. By the time it reached New York, it had been downgraded from a hurricane to a tropical storm.
The US National Hurricane Center is currently monitoring Tropical Storm Katia as it moves across the Atlantic. It is expected to reach hurricane strength tonight (August 31) but forecasts suggest it will veer north before hitting the Caribbean or the US.