The quake hit 256 km (157 miles) southeast of Chiniak, Alaska at a depth of 10 km at 0931 GMT, the U.S. Geological Survey said.
"If you are located in this coastal area, move inland to higher ground. Tsunami warnings mean that a tsunami with significant inundation is possible or is already occurring," Anchorage Office of Emergency Management said in a warning for Alaska and British Columbia.
Tsunami warnings for parts of Alaska and Canada and a tsunami watch for the entire U.S. west coast and Hawaii were issued.
Japan's meteorological agency said it was monitoring the situation but did not issue a tsunami alert.
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)
Follow NDTV for latest election news and live coverage of assembly elections 2019 in Maharashtra and Haryana.
Subscribe to our YouTube channel, like us on Facebook or follow us on Twitter and Instagram for latest news and live news updates.