North Korean leader Kim Jong Un claps 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 claps 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 claps during a celebration for nuclear scientists and engineers in this undated photo released by North Korea's Korean Central News Agency (KCNA) in Pyongyang on September 10, 2017. KCNA via REUTERS

September 11, 2017 10:12 AM (UTC+8)