Kim was born in Pyongyang.
On October 1, 2013, Kim became the first DPRK ambassador in Spain when his country opened its new embassy in Madrid. In September 2017 he was expelled as a persona non grata after a North Korean nuclear weapon's test on September 3, 2017. The Madrid embassy was later raided by members of Free Joseon on February 22, 2019, just prior to the 2019 North Korea–United States Hanoi Summit.
Replacing Choe Son-hui, the Vice Foreign Minister, Kim became the chief nuclear negotiator of the DPRK in February 2019. As the counterpart to Stephen E. Biegun, the American envoy, Kim participated in the Hanoi Summit on February 27 and 28 that was abruptly terminated.
In May 2019 the South Korean newspaper The Chosun Ilbo claimed that, in the aftermath of the failed Hanoi summit, Kim Hyok-chol and another four officials had been executed at Mirim Airport, Sadong-guyok, Pyongyang in March 2019. It was also indicated that some other participants, among them Kim Yong-chol, were sent to reeducation camps. The report remained unconfirmed and unsupported by other sources. In early June, state media of the DPRK published a photo of Kim Yong-chol at a public event with Kim Jong-un and CNN indicated, based on multiple sources, that Kim Hyok-chol was alive and in custody.
- Holloway, Henry (September 18, 2017). "North Korean ambassador EXPELLED as nuclear threat from Kim looms". Daily Star. Retrieved June 1, 2019.
- Lee, Jihye (February 22, 2019). "North Korea's Surprise New Nuclear Envoy Key to Trump-Kim Talks". bloomberg.com. Retrieved July 30, 2019.
- DPRK Establishes Relations with South Sudan
- Yoshihiro Makino (February 1, 2019). "North Korea replaces key negotiator with U.S." The Asahi Shimbun. Retrieved June 1, 2019.
- Victor Morton (May 30, 2019). "North Korea reportedly executes special envoy to U.S. over failed Trump-Kim summit". The Washington Times. Retrieved June 1, 2019.
- Justin McCurry (2019-05-31). "North Korea 'executes envoy to US' after Trump summit failures – report". The Guardian.
- Ben Feuerherd (2019-05-31). "Kim Jong Un executed officials after failed February summit with US: report". New York Post.
- Laura Bicker (May 31, 2019). "North Korea execution reports - why we should be cautious". BBC. Retrieved June 1, 2019.
- Adam Taylor, Simon Denyer, John Hudson (May 31, 2019). "Was a North Korean official executed? Mystery may cloud new talks with the U.S." The Washington Post. Retrieved June 1, 2019.CS1 maint: multiple names: authors list (link)
- Will Ripley (June 4, 2019). "'Executed' North Korean diplomat is alive, sources say". CNN. Retrieved June 4, 2019.