The three-day meeting of the North Korean central committee discussed key policy issues as well as plans for an upcoming congress of its ruling party -- North Korea's first in five years and expected next month.

Wrapping up the meeting on Thursday, Kim condemned "the wrong ideological viewpoint and inactive and irresponsible work attitude" of some officials, the state-run Korean Central News Agency (KCNA) said.

He also "pointed out the shortcomings and evil practices that must be corrected", KCNA said.

But he reserved praise for the North Korean soldiers fighting against Ukraine alongside Russia, of whom at least 600 have died and thousands more sustained wounds, according to South Korean estimates.

Their work, he said, "demonstrated to the world the prestige of our army and state as the ever-victorious army and genuine protector of international justice".

Analysts say Pyongyang is receiving financial aid, military technology, and food and energy supplies from Russia in return for sending troops.