The new weapons, tested at an undisclosed location Thursday, included an upgraded 240mm 24-tube multiple rocket launcher with an automated guidance system and an extended range of 56 miles, News.Az reports, citing UPI.

Also tested were shells for a 155mm self-propelled howitzer with an extended range of 40 miles and a special warhead for a tactical ballistic missile. KCNA said the warhead was “aimed at inflicting fatal damage on major targets including airfields, ports and power facilities of the enemy.”

Kim described the launches as a demonstration of the “great technological progress” made in implementing the party’s policy of “bringing about a change in the fire posture on the southern border.”

He added that the policy was intended not only to strengthen defenses but also to build a “deadly and destructive offensive posture to make no enemy dare to confront.”

Seoul, home to more than 10 million people, lies roughly 30 miles from the border, while the surrounding Gyeonggi Province is one of South Korea’s most densely populated and industrialized regions.

The tests come amid an extended push by Pyongyang to harden its military posture toward South Korea. Last month, Kim called for strengthening frontline defenses along the border to create an “impregnable fortress,” and Thursday’s weapons tests appear to represent the firepower component of that broader effort.

North Korea has ramped up fortification work near the Military Demarcation Line inside the DMZ, including the installation of barbed-wire fencing and preparations for mine-laying operations. South Korea’s Defense Ministry on Monday called the activity a violation of the armistice agreement that ended fighting in the 1950-53 Korean War.