PYONGYANG, June 26 (Xinhua) -- Kim Jong Un, top leader of the Democratic People's Republic of Korea (DPRK), oversaw on Thursday tests of multiple firepower systems in a bid to modernize the country's artillery and missile forces, the official Korean Central News Agency said Friday.

The tests involved the upgraded 240mm-caliber 24-tubular multiple rocket launcher system, tactical ballistic missile, and 155mm self-propelled gun-howitzer shells with an extended firing range, said the report.

The upgraded rocket launcher system employs an automated firepower system and a self-steered precise guidance system, with an extended firing range of 90 km. The tactical ballistic missile is equipped with a special mission warhead designed to inflict fatal damage on major enemy targets, including airfields, ports and power facilities.

The test of the gun-howitzer shells with an extended firing range of 65 km is also "of great military significance," it added.

Kim, general secretary of the Workers' Party of Korea and president of the State Affairs of the DPRK, said the tests marked an important occasion as they proved what he called the "great technological progress" in bringing about a change in the firepower posture of the country's armed forces and developing weapon systems on an automatic, long-range and ultra-precision basis.

The country's self-defense policy is not merely for enhancing defensive capabilities, but also "for further strengthening the deadly and destructive offensive posture to make no enemy dare to confront," Kim said, calling it "a defensive concept in the army-building and military action practice."