Kim Jong-un, grandson of the late Kim Il-sung, attended the grandiose ceremony with senior officials in front of tens of thousands of people gathered in Pyongyang's central square.
"Superiority in military technology is no longer monopolized by imperialists," he said in remarks broadcast on state television.
The display of military force came two days after the government suffered international humiliation with the failure of an attempted rocket launch.
The rocket exploded shortly after liftoff Friday and fell into the sea, marring the regime's plans to showcase a powerful nation as promised by the late founder and his son, Kim Jong-il.
The younger Kim praised the "military-first" ideology of his father and grandfather that built the world's fourth-largest standing army but has kept the nation poor and underdeveloped.
Kim Jong-un, who is said to be not yet 30 years old, has assumed key posts in a series of recent political events to cement his leadership of the secretive regime.//DPA