WASHINGTON, Aug. 30 (Xinhua) -- The U.S. National Hurricane Center (NHC) said on Friday evening that Hurricane Dorian has strengthened to category 4 as it moves toward southern United States.

Hurricane Dorian has a maximum sustained wind speed of 225 km per hour, and is moving at a speed of 16 km per hour toward the Florida panhandle.

According to the Saffir Simpson Hurricane Wind Scale, which categorizes hurricanes into five levels, anything of or above category 3 is considered a "major" hurricane.

Current estimation says Dorian will make landfall late Monday north of Miami, before turning north into the states of Georgia and South Carolina.

However, the NHC said the hurricane is likely to cause "life threatening storm surges and devastating hurricane-force winds" along the Florida coast, and advised local residents to execute their hurricane plan and follow local authorities' orders.

Florida Governor Ron DeSantis has declared a state of emergency, asking residents to prepare enough supplies to sustain seven days.

U.S. President Donald Trump has scrapped a planned visit to Poland this weekend, citing the need to monitor the hurricane. He had approved Florida's disaster declaration earlier Friday.