The U.S. National Hurricane Center (NHC) said Thursday the eye of Hurricane Bill was about 695 miles southeast of Bermuda and expected to reach Canada's Atlantic Maritime Provinces by Sunday.

The Miami-based hurricane center said Bill weakened slightly on Thursday was expected to regain power, as it encountered warmer waters that would boost its power.

The core of Hurricane Bill is expected to pass over open waters between Bermuda and the East Coast of the United States early Saturday, the NHC said.

Bermudian newspapers had reported that U.S. Secretary of State Hillary Clinton and her husband, former President Bill Clinton, were spending a brief private beach vacation on the island.

The State Department declined to officially confirm where Clinton was.

The NHC said Hurricane Bill was generating large swells which were pounding the northern Leeward Islands of the Caribbean.

In the coming days, swells will start affecting the Bahamas, Bermuda, most of the U.S. East Coast and the Canadian Maritime Provinces, it said.

These swells will likely cause extremely dangerous surf and life-threatening rip currents, the NHC said.