Joseph Yun, the top U.S. diplomat in charge of North Korean policy, announced his surprise retirement on Tuesday.
State Department spokeswoman Heather Nauert said on Twitter that Yun was leaving his position for personal reasons.
“Ambassador Joe Yun, a respected member of the Senior Foreign Service, has decided to retire for personal reasons, and the Secretary has reluctantly accepted his decision and wished him well,” Nauert said in a tweet.
“We are sorry to see him retire, but our diplomatic efforts regarding North Korea will continue based on our maximum pressure campaign to isolate the #DPRK until it agrees to begin credible talks toward a denuclearized Korean peninsula,” the State Department spokeswoman added on Twitter.
Yun told CNN on Tuesday that Secretary of State Rex Tillerson accepted his resignation “with regret.”
“It was completely my decision to retire at this time,” Yun said.
Yun’s job was to help rein in North Korea’s nuclear ambitions during years of tensions and had a reputation of being a proponent of dialogue when dealing with the country.
Nauert said Yun “served with distinction for more than 30 years, most recently as Special Representative for North Korean Policy and prior to that as U.S. Ambassador to Malaysia.”
Earlier in February, Yun was in South Korea and Japan to speak with officials about North Korea.