BEIJING (Kyodo) -- North Korea said Friday it conducted a test-fire of a new anti-aircraft missile system the previous day that was overseen by leader Kim Jong Un, with its full-scale production already underway, according to the official Korean Central News Agency.

The test proved the system's "combat fast response" and Kim expressed his gratitude for the efforts of researchers and munitions industry officials, saying the North Korean military will be equipped with "another major defense weapon system with laudable combat performance," KCNA said.

It remains unknown where the test-fire was conducted.

U.S. and South Korean military officials have said that Pyongyang may have received technical support from Moscow in the development of conventional weapons, including anti-aircraft missiles, in exchange for the deployment of North Korean troops to boost Russia in the Ukraine war.

KCNA also carried a statement from the North Korean Defense Ministry criticizing a large-scale annual joint military exercise conducted by South Korea and the United States, claiming it involved a drill aimed at removing Pyongyang's nuclear weapons.

The 11-day joint exercise through Thursday was "no more than a rehearsal of war of aggression aimed at invading and occupying" North Korea, the statement said. "The accumulated reckless military moves" of Washington and Seoul "can undoubtedly bring the gravest consequences they do not want," it warned.