The assessment came two days after North Korea confirmed for the first time that it had sent combat troops to help Russia recapture parts of the Kursk region.

In June last year, North Korean troops violated the border three times, prompting South Korea to fire warning shots. The incidents occurred when the Koreas were embroiled in Cold War-style campaigns like balloon launches and propaganda broadcasts, but they didn't develop into a major source of tensions.

It comes after the first official acknowledgement by Pyongyang and Moscow of North Korean troops' involvement in the Ukraine war.