Yun joined the
United States Foreign Service in 1985. In 2000, following tours in Hong Kong, Indonesia, Washington, DC, Paris, and Seoul, he was appointed Economic Counselor in the
U.S. Embassy in Bangkok, managing economic, labor and environmental issues. In 2004 he attended the
Asia Pacific Center for Security Studies, then took a 6-month assignment as senior adviser on the State Department Korea Desk. He returned to the
U.S. Embassy in Seoul in 2005 as the Minister-Counselor for Political Affairs, in charge of domestic, regional, and bilateral political issues. In 2009 Yun was posted back in Washington as Director of the State Department Office of
Maritime Southeast Asia. The following year he was named Deputy Assistant Secretary for Southeast Asia, and in 2011 he was appointed Principal Deputy Assistant Secretary for the
Bureau of East Asian and Pacific Affairs (EAP). During his time in EAP, Yun worked closely on President Obama's
Asian rebalance policy, especially in
Southeast Asia. Notable accomplishments included the diplomatic normalization of American relations with Myanmar, the establishment of a US mission for
ASEAN, and the inauguration of United States participation in the annual
East Asian Summit. For his work, the State Department has honored him with a Presidential Meritorious Service Award, three
Superior Honors Awards, and nine Foreign Service Performance Awards.
Ambassador to Malaysia Nominated by President
Barack Obama to serve as Ambassador to Malaysia on July 23, 2013, Yun was confirmed by the
U.S. Senate on August 1. As Ambassador, Yun emphasized stronger bilateral ties between the United States and Malaysia in all aspects: security, diplomatic, economic and people-to-people. During his three-year tenure, President Obama visited Malaysia twice, in 2014 and 2015. Prior to those trips, the last US president to visit Malaysia was
Lyndon B. Johnson in 1966. During his 2014 visit, President Obama and Prime Minister
Najib Razak signed the Comprehensive Partnership Agreement, pledging the United States and Malaysia to work closely together on security, business, education and technology issues. Yun also inaugurated the Oregon-Sabah Collaborative, bringing together private citizens, local governments, universities and civil society from the two states to promote educational exchange, forest and wildlife conservation, and business ties. For his work in this area, Yun received the Individual Achievement Award from the Oregon Consular Corps in 2016.
Special Representative for North Korea Policy On October 17, 2016, Yun assumed the office of
United States Special Representative for North Korea Policy, heading all coordination and implementation of U.S. policy toward
North Korea, especially concerning denuclearization. Concurrently, he held the office of Deputy Assistant Secretary for Korea and Japan, managing relations with America's principal allies in developing a coordinated policy toward North Korea. Yun was the key diplomat securing the release of American student
Otto Warmbier who had been imprisoned in North Korea for nearly a year and a half. In May 2017, Yun met secretly in
Oslo with North Korean officials to gain diplomatic access to the four American prisoners held in Pyongyang. Learning on June 6 that Warmbier had been in a vegetative state for the past 15 months, Yun flew with a medical team on an emergency mission to Pyongyang to secure his immediate release on "humanitarian grounds". He and the team returned Warmbier to his parents' care in the United States on June 12. While in Pyongyang, Yun also conducted a consular visit with the remaining American prisoners, the first since March 2016. As part of the agreement to release Warmbier, the North Koreans demanded $2 million as "repayment for medical expenses." Yun confirmed that he signed a pledge to pay that sum on the direct instructions of Secretary of State
Rex Tillerson. However, Trump said in April 2019 that no money had ever been paid. In the book
The Madman Theory by
Jim Sciutto, Yun stated that they started with believing that only
Kim Jong Un was unpredictable but they eventually had to accept that
Donald Trump was as unpredictable and that they had to be "careful what options you gave him (Trump)" because any option you put out there, he could use. Yun said that the
White House was looking at all options however extreme, but it was then-Secretary
James Mattis that refused to provide certain options for this reason.
Special Presidential Envoy for Compact Negotiations Yun retired from the U.S. State Department on March 2, 2018, He took positions as Senior Advisor with
The Asia Group and the
United States Institute of Peace and became a regular analyst on North Korea for
CNN. In March 2022 the Biden administration brought him back as Special Presidential Envoy For Compact Negotiations to revive the Compacts of Free Association negotiations with the three strategically important Pacific Island countries of Micronesia, Marshall Islands, and Palau, which had been stalled since December 2020. The COFA agreements were set to expire in 2023 for the first countries and in 2024 for Palau, raising US governments concerns about recent economic overtures from China as the deadline neared. Key issues included economic assistance stemming from historic U.S. nuclear testing on the islands, the continuing presence of U.S. military bases and the ballistic missile test site at Kwajalein Atoll, and
climate change mitigation. Negotiations were successfully completed and 20-year assistance agreements totaling $6.5 billion were signed in May 2023 with Micronesia and Palau and in October with the Marshall Islands. Yun retired as Special Presidential Envoy upon completion of the three agreements.
Chargé d'Affaires to South Korea On January 11, 2025, Yun was again called back to service by the Biden Administration to serve as acting Ambassador to South Korea. His arrival came in the midst of South Korea's
martial law crisis, instigated by President
Yoon Suk Yeol on December 3. Though Yoon's attempted coup failed, the situation in Seoul remained in flux, with no clear leader of the government and massive public protests. The State Department was deeply concerned to retain the strong bilateral alliance during what was predicted to be a "challenging" aftermath, especially given that the head of embassy was to become vacant on January 10 with the retirement of outgoing Ambassador
Philip Goldberg. During Yun's tenure as chargé, Korea had two acting presidents from the conservative
Peoples' Power Party (
Choi Sang-mok and
Han Duk-soo) prior to the election of opposition
Democratic Party of Korea (DPK) candidate
Lee Jae-Myung in June 2025. Yun served until October 24, 2025, when he returned to retirement. == See also ==