North Korea is celebrating the 105th birthday of the state’s founder, Kim Il-sung. North Korean leader Kim Jong-un attended a military parade in honour of his grandfather. New long-range and submarine-based missiles were part of the weapons displayed.The hermit state is on high alert after the US moved a nuclear-powered aircraft carrier to the region following North Korea’s latest long-range missile tests. North Korea warned the US it would retaliate any aggression in a ‘merciless manner’.