North Korean state media claimed "another important test" towards the development of a reconnaissance satellite had been carried out the week before.

Neighbouring South Korea described it as another ballistic missile launch.

Kim "expressed his great satisfaction over the fact that they confirmed the aerospace photographing method, the operating characteristics of high-resolution photographing equipment and the reliability of image transmission system through the recent important tests," state-run KCNA news agency reported.

He "highly appreciated the successes the NADA (National Aerospace Development Administration) has recently made", KCNA continued.

Development of the "reconnaissance satellite" is part of the strategy for monitoring Washington's "aggression troops... and its vassal forces in and around the Korean Peninsula," Kim said, according to KCNA.

North Korea is under biting international sanctions for its nuclear weapons programmes, but peaceful satellite launches are not subject to the same level of restrictions -- although they use much of the same technology.

The development of a military reconnaissance satellite -- along with a string of banned weaponry, including hypersonic missiles, tested in January -- is officially one of Pyongyang's key defence projects, as outlined by Kim last year.

Pyongyang has doubled down on Kim's drive to modernise its military as it ignores US offers of talks and threatens to abandon a self-imposed moratorium on testing long-range missiles and nuclear weapons.