Kim made the comments on Friday during a speech at the groundbreaking ceremony for a memorial for North Korean soldiers who fought alongside Russian troops in Russia's Kursk region during Moscow's ongoing war with Ukraine, KCNA said.
"The years of militant fraternity, in which a guarantee has been provided for the long-term development of the bilateral friendship at the cost of precious blood, will advance non-stop," Kim said, according to KCNA.
Challenges by "domination and tyranny" cannot hinder the two countries' ties, he said. The event was the latest public honouring of North Korean troops who fought in Russia to repel an incursion by Ukrainian forces.
Kim and Russian President Vladimir Putin have signed a mutual defence pact. North Korea has sent soldiers, artillery ammunition and missiles to Russia to support Moscow's full-scale invasion of Ukraine.
Kyiv and Seoul estimate North Korea deployed more than 10,000 troops to the war in return for economic and military technology assistance from Russia. South Korea's intelligence agency estimated in September that about 2,000 North Korean soldiers had been killed in the fighting.
Kim met with Russian Security Council Deputy Chairman and the head of the United Russia party Dmitry Medvedev in Pyongyang earlier in October.
Putin remained defiant on Thursday after US President Donald Trump hit Russia's two biggest oil companies with sanctions to pressure the Kremlin leader to end the war.
Trump will visit South Korea, North Korea's bitter rival, next week.
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