According to Fyodor Tertitskiy of NK News, he was born Kim Myong-sam to a Korean-Chinese family in the village of Dapu Shihe in Manchuria, in what is now the Liaoning province of China, in 1928.

[7] His elevation to Minister of Foreign Affairs is believed to have occurred as part of a reorganization of the diplomatic bureaucracy after the Rangoon bombing in October 1983.

[10] The journalist and academic Don Oberdorfer described Kim as enigmatic, rigid in his official role, personally pleasant, highly intelligent, and an important figure behind the scenes in Pyongyang.

[13] Kim represented North Korea at the 2015 Victory Day parade in Moscow on May 9, 2015, commemorating the 70th anniversary of the defeat of Nazi Germany in World War II.

As representative of the Democratic People's Republic of Korea, he attended the investiture ceremony of Andrés Manuel López Obrador as president of Mexico on December 1, 2018.

He retired on April 11, 2019 in a government reshuffle, aged 91, after almost 21 years as President of the SPA Presidium and roughly four decades as Party Politburo member (having first been elected to the body in August 1978).