A state-run North Korean television agency released footage Tuesday of Supreme Leader Kim Jong Un watching a test missile launch. Reportedly from a June test launch, the footage was released as tension along the Demilitarized Zone between North Korea and South Korea remained high.

North Korea has a history of releasing footage or photo stills of military exercises as a way to show its military prowess to neighboring nations. The footage released Tuesday reportedly came from a June test launch in which the North Korean military fired three short-range antiship missiles off its eastern coast. Kim applauded, smiling, as the missiles appeared to strike their targets in the video.

The type of missile fired in the test was a KN-01, South Korean officials told CNN in June. KN-01s have a range of about 120 kilometers, or 75 miles. The same video showed Kim watching other military exercises and speaking to military officials.

Pyongyang also reportedly tested a rocket engine Aug. 20 in preparation for festivities marking the 70th anniversary of the founding of the ruling Worker's Party.

Strained relations between Pyongyang and Seoul reached new heights after two South Korean soldiers were maimed Aug. 4 after stepping on land mines reportedly placed by North Korea near the Demilitarized Zone. Artillery fire was then exchanged between the two nations on several occasions throughout August, but the conflict has largely de-escalated in the past week.

"We do not yet know how military matters will fluctuate in North-South relations. We'll have to wait and see," said South Korean Defense Ministry deputy spokesman Na Seung-yong Monday. "Our military has a fundamental obligation to keep an eye on the situation," he said.