The launch proved the system's "combat fast response", the Korean Central News Agency (KCNA) said, and came as South Korea wrapped up a major annual joint military exercise with the United States.

Kim praised the anti-aircraft system, saying North Korea's army would be "equipped with another major defence weapon system with laudable combat performance," KCNA wrote.

It did not specify where the test took place.

Seoul said last Monday the North fired "multiple unidentified ballistic missiles" after it began joint drills involving US soldiers stationed in South Korea, which ended this Thursday.

In a separate statement Thursday, an unnamed spokesperson for the North's defence ministry denounced the military exercise as "no more than a rehearsal of war of aggression".

Pyongyang also carried out a test-launch of strategic cruise missiles in the Yellow Sea in late February, which it said showed off "counterattack capabilities".

Relations between Pyongyang and Seoul have been at one of their lowest points in years, with the North launching a flurry of ballistic missiles last year in violation of UN sanctions.

The two Koreas remain technically at war since their 1950-1953 conflict ended in an armistice, not a peace treaty.