Government officials are scrambling to prepare for a powerful hurricane heading toward the U.S. east coast.

The governors of North Carolina, Virginia, Maryland, Delaware, New Jersey and New York have declared states of emergency to free up resources ahead of Hurricane Irene, which is expected to make landfall in North Carolina on Saturday. President Barack Obama has also declared a state of emergency for North Carolina.

The U.S. National Hurricane Center says Irene has slightly weakened, with maximum sustained winds of 175 kilometers an hour, but it remains a dangerous category two storm on a five-point scale measuring a storm's intensity and potential destructive power. Forecasters expect it to strengthen as it nears the North Carolina coast.

Irene has killed at least one person in Puerto Rico and two in the Dominican Republic.

Hurricane watches and warnings have been issued for much of the east coast, and authorities in some of the affected areas are already evacuating residents and beach visitors. New York City Mayor Michael Bloomberg has ordered hospitals and nursing homes in low-lying areas of the city to evacuate.

The threat of Hurricane Irene led organizers to postpone Sunday's dedication of a memorial to the legendary civil rights leader Martin Luther King, Jr.

Craig Fugate, the head of the Federal Emergency Management Agency, told reporters Thursday Irene will have an impact “well inland,” both from flooding and winds, which can topple trees and cause power outages.

The National Hurricane Center says the storm is expected to produce rainfall accumulations between 15 and 25 centimeters throughout the affected areas, which could cause widespread flooding and life-threatening flash floods. Some parts of the U.S. mid-Atlantic and New England regions are already saturated from recent heavy rains.

Irene is the first hurricane to seriously threaten the United States in three years