North Koreans welcome leader Kim Jong-un with a standing ovation.
State television reported that Jong-un called for troops to be ready for action as the U.S. and South Korea host joint-military drills on Monday.
"If the enemies fire even a single shell on our inviolable territory and territorial waters, the Korea People's Army should deal prompt deadly blows at them," he said.
Jong-un attended the anniversary celebration of his father's military legacy with his wife Ri-Sol-ju and aunt.
The annual U.S. and South Korean military exercise involves more than 86,000 officers and focuses on readiness, deterrence and defence.
North Korean has denounced the drill, describing it as a prelude to war.
