Kim Jong-un’s show of force involved fighter jets, attack submarines and hundreds of artillery units.
Shocking photos show an entire beach on the east coast of the hermit state filled with fire and explosions as soldiers carry out drills.
Jets are shown taking off and landing while submarines emerge from the water off the port town of Wonsan.
Between 300 and 400 artillery units are thought to have been used in the drills, which have been confirmed by South Korea.
They said they were monitoring the situation, which they described as a “large-scale firing drill” and said they were “firmly maintaining readiness”.
A North Korea propaganda newspaper based in Pyongyang said: “There is no limit to the strike power of the People’s Army armed with our style of cutting-edge military equipment including various precision and miniaturised nuclear weapons and submarine-launched ballistic missiles.”
South Korea has also held joint drills with America in response, sending their own message to Pyongyang.
This 11-day exercise drills has begun in a similarly awe-inspiring manner, with hundreds of personnel involved in the explosive war games.