According to Thae, North Korean dictator Kim Jong Un is "desperate in maintaining his rule by relying on his [development of] nuclear weapons and ICBM." He was using an acronym for intercontinental ballistic missiles — a long range rocket that in theory would be capable of hitting the U.S.
"Once he sees that there is any kind of sign of a tank or an imminent threat from America, then he would use his nuclear weapons with ICBM," he added in an exclusive interview on Sunday.
Thae was living in London and serving as North Korea's deputy ambassador to the United Kingdom when he and his family defected to South Korea and were announced to the world in August.
He was not directly involved in North Korea's weapons program but believes his country "has reached a very significant level of nuclear development."