North Korean leader Kim Jong Un reacts during a celebration for nuclear scientists and engineers who contributed to a hydrogen bomb test, in this undated photo released by North Korea's Korean Central News Agency (KCNA)

North Korean leader Kim Jong Un reacts during a celebration for nuclear scientists and engineers who contributed to a hydrogen bomb test, in this undated photo released by North Korea’s Korean Central News Agency (KCNA)

North Korean leader Kim Jong Un reacts during a celebration for nuclear scientists and engineers who contributed to a hydrogen bomb test, in this undated photo released by North Korea's Korean Central News Agency on Sept 10. Photo via Reuters

September 14, 2017 3:30 PM (UTC+8)