A seasoned Japanese-American diplomat has taken the helm of the Korea desk at the U.S. State Department amid efforts to boost cooperation on trade and the North Korean nuclear issue.

Joy Yamamoto recently took office as director of the Korea desk after serving as minister-counselor for economic affairs at the U.S. Embassy in Seoul.

She succeeds Mark Lambert, who was moved to a new role handling North Korea issues at the deputy assistant secretary level.

A former newspaper journalist, Yamamoto has previously worked on the department's Korea, China and Indonesia desks. She has also served as director of the Office of Economic Policy in the department's Bureau of East Asian and Pacific Affairs.

Her overseas assignments include postings in the Philippines, New Zealand, Trinidad and Brazil.

In Seoul, Yamamoto handled trade issues, including the renegotiation of the South Korea-U.S. free trade agreement and economic sanctions on North Korea, according to sources familiar with her role.

Her appointment nearly completes the lineup of senior U.S. diplomats handling Korea affairs.

In recent months, former Ford Motor Vice President Stephen Biegun took office as U.S. special representative for North Korea, and Harry Harris filled a longstanding vacancy as U.S. ambassador to Seoul.

Marc Knapper, who until recently served as acting U.S. ambassador to South Korea, also moved into the job of acting deputy assistant secretary for Korea and Japan issues.

Still to be named is the assistant secretary of state for East Asian and Pacific affairs, the top U.S. diplomat for the region.

Source: Yonhap News Agency