North Korean leader Kim Jong-un has stressed the need for nuclear deterrence as self-defense at a meeting with nuclear scientists and other officials who contributed to last week's nuke test, Pyongyang's state media said Monday.

Kim held a photo session with nuclear scientists, technicians, soldiers and other officials who have contributed to what the North claimed was a successful test of a hydrogen bomb on Wednesday, according to the Korean Central News Agency. It did not reveal the time of his activity.

North Korea conducted its fourth nuclear test last week, claiming that the move is an act of self-defense in the face of nuclear war threats by the United States

Seoul has vowed to make the North "pay the price" for its nuclear provocation and resumed its anti-North Korea loudspeaker broadcasts after about four months of silence, a move certain to irritate the North.

One of Washington's B-52 strategic bombers flew in the skies of South Korea on Sunday in a show of force. The plane was armed with nuclear missiles and "bunker buster" bombs that are capable of bombarding North Korea's underground facilities.

The KCNA said Kim expressed the expectations and conviction that those involved in the nuke test will "make uninterrupted advances and innovation with the same vim and vigor with which they succeeded in the H-bomb test." (Yonhap)