North Korea has described its firing of rocket artillery and an apparent short-range ballistic missile over the weekend as a regular and defensive military exercise and ridiculed South Korea for criticizing the launches.

Pyongyang's state media on Thursday carried a statement by an unnamed military spokesman who called Seoul's criticism a "cock-and-bull story." Seoul's presidential Blue House and Defense Ministry have raised concern that Saturday's launches went against the spirit of an inter-Korean military agreement reached last year to cease all hostile acts.

A separate statement by a North Korean foreign ministry spokesman described the launches as a "routine and self-defensive military drill."

The launches were a likely sign of Pyongyang's frustration at stalled diplomatic talks with Washington meant to provide coveted sanctions relief in return for nuclear disarmament.