[2] Jon played a key role in the production and development of North Korean defense industry for more than four decades before retiring in 2011.

[2] Jon supervised the development of the country's long-range ballistic missile programmes and was involved with its first test of a nuclear device in 2006 directly.

[2] Jon was sanctioned by the United Nations as a result of his involvement in the country's nuclear and missile weapons programmes.

[2] He was born in Musan County, in North Hamgyong Province, and was educated at the Ural Engineering College in the Soviet Union, where he graduated in 1950.

[3] He has since held a number of positions within the North Korean military and government, and was appointed member of the National Defense Commission in February 2009.