Shafaq News/ On Friday, the state-run Central News Agency of North Korea reported the testing of an underwater nuclear weapons system as a reaction to joint military exercises conducted earlier in the week between South Korea, the United States, and Japan.

According to a statement announced by the North Korean Ministry of Defense, these exercises “seriously threatened the security” of North Korea.

In response, Pyongyang held an important test of its underwater nuclear weapon system (HIL-5-23) under development in the East Sea of Korea.

After holding live-fire drills near the western maritime border with South Korea on Sunday, North Korea’s army claimed to launch a ballistic missile.

Joint chiefs of staff in Seoul stated that “North Korea fired an unknown ballistic missile towards the East Sea,” also known as the Sea of Japan.

The missile launch occurred shortly after North Korea fired artillery shells near the maritime border with South Korea, prompting Seoul to conduct similar firing exercises in response.

North Korean leader Kim Jong Un, in a late December ruling party meeting, vowed to expand the country’s nuclear arsenal and launch additional spy satellites in response to what he described as “offensive moves” led by the United States.