The government on Friday named Japan's ambassador to South Korea, Koji Tomita, as its new envoy to the United States, effective the same day, ahead of President-elect Joe Biden's inauguration next month.

Tomita, 63, is known to have ties with people close to Biden. He succeeds Shinsuke Sugiyama, who assumed the post in January 2018.

Tomita previously served as minister at the Japanese Embassy in Washington and also headed the Foreign Ministry's North American Affairs Bureau, working with the administration of then-President Barack Obama in which Biden served as vice president.

During his stint as ambassador to South Korea that only began in October last year, Tomita faced the challenge of improving bilateral relations that have sunk to a historic low over wartime labor and trade issues.