Ri has served as a diplomat to Switzerland, and has represented North Korea at the United Nations mission in Geneva.

He is the third North Korean foreign minister to speak before the United Nations General Assembly.

In his statement to the assembly, described as unsurprising, Ri called for the United States to work toward a peace treaty in Korea in exchange for "dramatic improvement" in security of the Korean peninsula.

He met with Indian foreign minister Sushma Swaraj to discuss North Korean nuclear program and regional security issues.

[15] He was replaced by Kim Hyong-jun in his diplomatic responsibilities between late 2019 and 2020, and removed from the Politburo and the State Affairs Commission.

During his career, Ri took care of many personal and financial affairs of Kim,[2] including his Swiss bank accounts.