Joseph Yun, the U.S. special representative for North Korea policy, in Tokyo, Feb. 1. (Shizuo Kambayashi/AP)

The State Department’s point man on North Korea, Joseph Yun, will leave his post on Friday, amid glimmers of hope that Pyongyang might finally be willing to sit down for talks with Washington.

Yun, 63, is retiring as special representative for North Korea policy and deputy assistant secretary for Korea and Japan after more than three decades of service.

His departure reflects widespread frustration within the State Department at diplomats’ relative lack of power in the Trump administration, according to someone familiar with Yun’s thinking.

It will leave another gaping hole in the United States’ staffing on Korean issues. Washington has still not nominated an ambassador to South Korea, 13 months into the Trump administration. Victor Cha had been in the running for the job, but the administration abruptly scrapped his candidacy last month.

Yun confirmed that he would be retiring and that Friday would be his last day.

“This is my own personal decision,” Yun told The Washington Post. “Secretary Tillerson has told me he appreciates my service and did not want me to go, but he accepts it reluctantly.”

State Department spokeswoman Heather Nauert confirmed that Rex Tillerson had “reluctantly accepted” Yun’s decision and wished him well.

“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,” Nauert said, using the abbreviation for North Korea’s official name.

Yun was the main person in the State Department dealing with the North Korea problem, and he traveled to Seoul and Tokyo frequently to coordinate with the U.S. allies. 

He also traveled to Pyongyang last June to collect Otto Warmbier, the University of Virginia student who had been detained in North Korea for 17 months, almost all of that time in a coma. 

Yun brought Warmbier back to the United States on a medical evacuation flight. The 22-year-old died six days later.

During that trip to Pyongyang, Yun was able to see the three other Americans being detained in North Korea. That was the last time outsiders have seen or heard from the three men.

Yun, a strong advocate of engagement with North Korea, has been arguing in favor of dialogue with Pyongyang during the last year of increased tensions. 

He has been the U.S. government’s main interlocutor with North Korea’s diplomats assigned to the United Nations, the working-level hotline called “the New York channel.” Yun has been meeting regularly with his counterpart there, Pak Song Il.

Last May, he met in Oslo with the head of the Americas division in North Korea’s Foreign Ministry, Choe Son Hui, to arrange for Warmbier’s release. Choe is thought to have a direct line to the North Korean leader, Kim Jong Un.

Still, his efforts to promote dialogue with North Korea have been stymied by a president who has threatened to rain “fire and fury” on the North Korean leader, whom Trump has derided as “little rocket man.”

At the Olympic Games in South Korea, which closed Sunday, South Korean President Moon Jae-in tried to promote dialogue, eliciting a sign from North Korea’s representatives that they are willing to talk to the Trump administration.

But the signals have been mixed, to say the least. The White House reported that Vice President Pence was prepared to meet with North Korean officials during the Olympics Opening Ceremonies but that they backed down at the last moment. The administration has kept up its drumbeat of “maximum pressure” on Pyongyang.

North Korea’s chief delegate to the Closing Ceremonies, Kim Yong Chol, indicated a renewed willingness for talks, Moon said, although it remains unclear whether denuclearization would be on the agenda.

Many Foreign Service officers have expressed frustration with the Trump administration’s unwillingness to listen to the State Department.

The top career diplomat in the State Department, Undersecretary of State for Political Affairs Thomas A. Shannon Jr., announced this month he would be retiring after 35 years in the Foreign Service.

Yun, who was born in South Korea but is a naturalized American citizen, joined the State Department in 1985.

He served as head of the political division in the U.S. Embassy in Seoul in the early 2000s, including when Roh Moo-hyun was president and his chief of staff was Moon , the current president. It was Yun who wrote the now-famous diplomatic cable describing Choi Tae-min, the spiritual adviser to disgraced former South Korean president Park Geun-hye, as a “Korean Rasputin.”

Between 2013 and 2016, during the Obama administration, Yun served as ambassador to Malaysia.