North Korean leader Kim Jong-un inspected the country's first military reconnaissance satellite and gave the green light for its next action plan, Pyongyang's state media said Wednesday, adding that the satellite is "ready for loading" on a rocket.

Kim made the on-site inspection to the Non-permanent Satellite Launch Preparatory Committee a day earlier to check the overall status of the spy satellite and approved of its "future action plan," the Korean Central News Agency said, in a move that signals the launch could be imminent.

"After acquainting himself in detail with the work of the committee, he inspected the military reconnaissance satellite No. 1 which is ready for loading after undergoing the final general assembly check and space environment test," it said in an English-language dispatch.

Kim stressed that the successful launch of the satellite is an "urgent requirement" under the prevailing security environment and a process of "bolstering up the defence capabilities on a top priority basis."

He also said "the more desperately the US. imperialists and South Korean puppet villains" escalate their confrontational moves against the North, "the more fairly, squarely and offensively" it will exercise its right to self-defence to deter them.

The KCNA did not provide further details on the "future action plan," including the exact date of the launch.

Experts said the North is likely to calibrate the ideal timing of the satellite launch, considering climate conditions and major political events.

"As the next step, North Korea will mount the satellite inside the pairings at the top end of the projectile," Kim Dong-yub, a professor at the University of North Korean Studies, said. "The launch seems likely as early as June depending on the readiness of the delivery vehicle."

Photos released by the KCNA showed Kim's daughter Ju-ae accompanying the inspection in lab gowns and head caps.

The latest inspection marks Kim's first public activity since his on-site visit to the North's space development agency on April 18, when he announced that the North has completed building its first military spy satellite.

In December last year, Pyongyang said it had conducted an "important final-stage" test at its rocket launching facility for the development of its first reconnaissance satellite.

The development of spy satellites was one of the key weapons projects announced by Kim during a ruling party meeting in January 2021. (Yonhap)