Stephen Bosworth, former U.S. Ambassador to South Korea and special representative for North Korea policy, died on Sunday at the age of 76, Yonhap News Agency reported late on Monday.

As a Korea expert, Bosworth was appointed U.S. special representative for North Korea policy in 2009 by former U.S. Secretary of State Hillary Clinton and served until October 2011. Bosworth also served as a U.S. Ambassador to South Korea from 1997 to 2001 and an executive director for the Korean Peninsula Energy Development Organization (KEDO) from 1995 to 1997.