The test-firing, which took place Saturday, showed that the two "improved" missile weapon systems had "superior combat capability", the Korean Central News Agency (KCNA) reported.

The KCNA report did not explain the new missiles in any detail, only that their "operation and reaction mode is based on unique and special technology". It also did not specify where the test had been conducted.

"The firing particularly proved that the technological features of two types of projectiles are very suitable for destroying various aerial targets," KCNA said.

Photos released by KCNA showed air defence missiles soaring into the sky and the flash of the purported interception of an incoming projectile.

Kim is pictured listening to a briefing by a military official, a pair of binoculars sitting next to him on his desk.

The North Korean leader separately communicated an "important task" for the defence science sector to carry out before a key party meeting, the report added.

South Korea's military said Saturday it had fired warning shots at several North Korean soldiers who briefly crossed the heavily militarised border separating the two countries earlier in the week.

UN Command put the number of North Korean troops that crossed the border on Tuesday at 30, Yonhap news agency reported Sunday.

Pyongyang state media quoted Army Lieutenant General Ko Jong Chol as saying the incident was a "premeditated and deliberate provocation".

"This is a very serious prelude that would inevitably drive the situation in the southern border area where a huge number of forces are stationing in confrontation with each other to the uncontrollable phase," Ko said.

- Ukraine lesson -

Analysts say Pyongyang appears to be accelerating the development of air defence missiles aimed at countering drones, citing the KCNA report that specifically mentioned "drones and cruise missiles".

"The North is bolstering air defence missiles against low-altitude flying drones and cruise missiles," said Hong Min, a senior analyst at the Korea Institute for National Unification.

The development of such air defence missiles attests to "Pyongyang's recognition of the necessity to enhance its capabilities... based on lessons it learned" fighting in Russia's war against Ukraine, he added.

South Korean and Western intelligence agencies have said the North sent over 10,000 soldiers to Russia in 2024 -- primarily to the Kursk region -- along with artillery shells, missiles and long-range rocket systems.

Around 600 North Korean soldiers have been killed and thousands more wounded fighting for Russia, Seoul has said.

New South Korean President Lee Jae Myung has sought warmer ties with the nuclear-armed North and vowed to build "military trust", but Pyongyang has said it has no interest in improving relations with Seoul.