The launch of the cruise missile "had no impact on the security of neighboring countries and has nothing to do with the regional situation," the report said.
The launch of the missile is "a process of constant updating of the weapon system," which is "a regular and obligatory activity of the administration and its affiliated defence science institutes," KCNA cited the administration as saying.
Last week, a spokesman for the North Korean National Defense Ministry said in a statement carried by KCNA that Pyongyang had tested the still under-development "underwater nuclear weapon system Haeil-5-23" in the Sea of Japan in response to joint three-day naval exercises by the United States, South Korea and Japan involving a US nuclear carrier and other warships.