(Reuters) - Florence, a Category 1 hurricane, continued to strengthen in the central Atlantic and was expected to become a major hurricane by Monday night, the U.S. National Hurricane Center said in its latest advisory on Sunday.

The hurricane was located about 560 miles (905 kilometers) northeast of the northern Leeward Islands, packing maximum sustained winds of 90 miles per hour (150 km/h), the Miami-based weather forecaster said.

Florence was expected to remain an extremely dangerous, major hurricane and was forecast to approach the southeastern coast of the United States on Thursday, the NHC added.