ARI SHAPIRO, HOST:
The Trump administration is losing a key diplomat on North Korea. Career State Department employee Joseph Yun is formally retiring at the end of this week. Some experts worry that will leave a big hole in diplomatic efforts to resolve the nuclear standoff with Pyongyang. NPR's Michele Kelemen reports.
MICHELE KELEMEN, BYLINE: State Department spokesperson Heather Nauert it calls it a personal decision, and she says Secretary of State Rex Tillerson was reluctant to accept Joseph Yun's departure.
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HEATHER NAUERT: He is very well-respected across the administration and in other places as well, but I feel fully confident that we have the appropriate people in place who can handle everything he did and more. Our policy remains the same. We are just as engaged in North Korea. Taking one person out of the mix does not change things in any way.
KELEMEN: Yun has been with the State Department for more than three decades, most recently serving as special representative for North Korean policy. He kept open the diplomatic back channels with North Korea and traveled to Pyongyang last year on behalf of the Trump administration to pick up the jailed American student Otto Warmbier, who died soon after he was evacuated. Yun's departure comes just as North Korea signals it's ready to talk to the U.S., but Nauert says it's wrong to read too much into this.
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NAUERT: We continue to push ahead and forge ahead with our maximum pressure campaign that extends well beyond the State Department, also the Department of Treasury, the White House, the NSC and other Cabinet departments as well.
KELEMEN: But North Korea watchers are worried that Yun will be missing in that interagency debate. Jon Wolfsthal, who was a U.S. government inspector in North Korea and a White House official during the Obama administration, describes Yun as a tireless advocate for a diplomatic way out of the nuclear standoff with North Korea.
JON WOLFSTHAL: He had a tremendous reserve of energy both in frustrating times during the Obama administration when we couldn't get any traction with North Koreans and, I think, during the Trump administration where it's been frustrating just with the internal dynamics. He has gone to work every day and tried to figure out how we avoid a military clash and how we actually make progress on this issue. And I think he's going to be sorely missed.
KELEMEN: Especially at a time when there's increasing talk about military options. Wolfsthal says there are few like Yun in this administration.
WOLFSTHAL: While there are a lot of people working on the sanctions effort, they're working on the pressure campaign, they're working on the military effort, there really is nobody with Joe Yun's departure that is working the diplomatic side, specifically because we also don't have a U.S. ambassador in South Korea who can be coordinating closely with our allies in Seoul.
KELEMEN: A career diplomat is filling in as ambassador in South Korea while the Trump administration decides who to nominate. There are still many diplomatic vacancies in this administration. Asked whether the White House was planning to fill Yun's job as North Korea envoy, spokesperson Sarah Sanders would only say she has no personnel announcements to make. Michele Kelemen, NPR News, the State Department. Transcript provided by NPR, Copyright NPR.