Pyongyang called the purpose of missile launches

According to the state Agency, it was a training shooting. Their goal was to test the performance of long-range large-caliber rocket launchers for the sake of “protecting political sovereignty.”

North Korean state Agency confirmed missile launches from the East coast in the country last Saturday, specifying that it was a training shooting.
The purpose of the exercise was to test the performance of “large-caliber long-range rocket launchers and tactical guided weapons.

It also emphasizes that the exercises the leader of the DPRK Kim Jong-un led the exercises personally. He expressed “great satisfaction” with Saturday’s exercises and stressed that North Korean troops should remain “in a state of high readiness” and increase their combat capability to “protect the political sovereignty and economic independence of the country,” the Agency said.