North Korean leader Kim Jong Un chaired two days of military drills 'simulating a nuclear counterattack'. The latest drills come as the biggest warning to the United States and South Korea as they hold their largest-ever joint military drills. North Korean drills also included firing of a short-range ballistic missile carrying a mock nuclear warhead. The drills were the fourth show of force from Pyongyang amid U.S-South Korea drills. Expressing confidence, the North Korean leader said that the country would reach its goals only 'when the nuclear force is perfected as a means of actually capable of mounting an attack on the enemy'. Watch this video for details.