The U.S. Ambassador to Korea, Sung Kim, is expected to step down before his term ends.
Citing diplomatic sources, local media reported that Kim told acquaintances at a meeting on Monday he will leave the position sometime this summer.
The news has fueled speculation that he will be succeeded by Mark Lippert, a longtime adviser to President Barack Obama and Defense Secretary Chuck Hagel.
Kim, the first Korean American to serve in the role, began his term in November 2011.