SEOUL, South Korea - North Korean leader Kim Jong Un oversaw a successful test of a solid-fuel engine for a "new-type intermediate-range hypersonic missile", Pyongyang's state media said Wednesday.

The test was carried out on Tuesday by the North's Missile Administration at the Sohae Satellite Launching Ground in the northwest of the country, according to the official Korean Central News Agency (KCNA).

"A ground jet test of a solid-fuel engine for new-type intermediate-range hypersonic missile, which is of another strategic value," KCNA said.

The North Korean leader said the "military strategic value of this weapon system is appreciated as important as ICBM", it added, referring to an intercontinental ballistic missile.

Pyongyang said late last year that it had conducted a series of ground tests for a new type of solid fuel engine for its intermediate-range ballistic missiles (IRBMs).

Pyongyang's latest announcement came a day after North Korea said Kim oversaw drills involving "newly-equipped super-large" multiple rocket launchers, with emphasis on "perfect preparedness to collapse the capital of the enemy".

Testing a more technologically advanced solid-fuel missile has long been a key goal for Kim.

The North claimed last year it had successfully tested its first solid-fuel ICBM -- the largest, longest-range category of ballistic missile -- hailing it as a key breakthrough for the country's nuclear counterattack capabilities.

Experts say solid-fuel missiles typically have a higher level of operational ease and safety, compared to liquid-fuel weapons.

Solid-fuel missiles don't need to be fuelled before launch, making them harder to find and destroy, as well as quicker to use.