North Korean leader Kim Jong-un oversaw a ground test of a solid fuel rocket engine, state media reported Sunday, in the latest sign of Pyongyang's push to reinforce its strategic weapons arsenal.

Solid fuel engines allow for faster missile launches because they require little preparation before ignition, and defense experts believe North Korea plans to use them for the intercontinental ballistic missiles that is developing.

The testing of this engine, made of carbon fiber composite material, was “part of the national defense development plan in the period of the new five-year plan,” the state news agency KCNA reported.

Pursuing such high-impulse engines “is in line with the national strategy and the military demand for modernization of strategic forces,” Kim was quoted as saying by KCNA.

The outlet did not indicate the location or date of the test.

Photos released by the agency show Kim inspecting what appears to be part of the engine.

Another photo is a close-up shot of flames coming out of a ground-mounted engine.

Kim witnessed the ground test of the newly improved engine, made of a carbon fiber composite material, according to KCNA, which reported that the engine's maximum power output is 2,500 kilotons, up from approximately 1,971 kilotons recorded in a similar test with a solid-fuel engine was developed in September.

According to observers, the push to increase engine power is likely related to efforts to fit multiple warheads onto a single missile to increase the chances of overcoming US defenses.

Kim, heir to the dynasty that rules the isolated Asian country with an iron fist, maintained that North Korea's defense capabilities had entered "a significant phase of change" in the building of its strategic forces.