The Joint Chiefs of Staff(JCS) said Friday that North Korea fired two projectiles presumed to be short-range ballistic missiles eastward from the inland region North Pyongan Province.

The launches come just three days after the regime claimed it successfully completed its final test of a hypersonic missile on Tuesday and is the North’s third demonstration of ballistic capabilities in a little over a week.

While military authorities are reportedly analyzing details of the latest launch, the missiles were known to have registered low altitudes and traveled between 300 and 400 kilometers.

Some military experts suspect they may be KN-23, which was modeled after Russia’s Iskander missile, or a North Korean version of the U.S. Army Tactical Missile System (ATACMS).

The latest launches came after the U.S. imposed new sanctions on six North Koreans linked to the regime’s missile development program, apparently in response to the North's two previous ballistic missile launches.

In a foreign ministry statement through the Korean Central News Agency earlier in the day, North Korea warned of a "stronger and certain reaction" if the U.S. adopts a confrontational stance, referring to its new sanctions.

The JCS said the South Korean military is closely monitoring the situation while maintaining a readiness posture. The presidential office’s National Security Office also convened for an emergency virtual meeting Friday afternoon to discuss the North’s latest actions.