Kim's visit to the factory was reported a day after Pyongyang said it had carried out a test-fire of two strategic long-range cruise missiles in a show of "combat readiness" against foreign threats.

Accompanied by top officials from North Korea's missile programme, Kim said the new weapons system would serve as his military's "main strike means", according to the state-run Korean Central News Agency (KCNA).

He said the new multiple rocket system was a "super-powerful weapon system as it can annihilate the enemy through sudden precise strike with high accuracy and devastating power", KCNA said.

The system would be "used in large quantities for concentrated attack in military operations", KCNA added.

State media images showed Kim standing next to the massive new missile systems in a vast factory with propaganda on the walls.

North Korea is still technically at war with the South and its vast artillery arsenal has long been believed by analysts to be central to its strategy should conflict break out on the peninsula.

A 2020 study by the RAND think tank assessed that North Korean artillery systems could inflict 10,000 casualties in just an hour if targeting major population centres like the South Korean capital Seoul.

Pyongyang has also significantly increased missile testing in recent years.

Analysts say this drive is aimed at improving precision strike capabilities, challenging the United States as well as South Korea, and testing weapons before potentially exporting them to Russia.