North Korean leader Kim Jong Un said on Sunday that he was all in on Russia's war against Ukraine.

Pyongyang's foreign ministry wrote that Kim had met with Russia's foreign minister, Sergey Lavrov, during which the two leaders pledged to "strengthen strategic and tactical cooperation" between their countries.

Kim said he was "willing to unconditionally support all measures taken by the Russian leadership in relation to the fundamental resolution of the Ukrainian situation," the report said.

It comes as CNN reported on July 2, citing a Ukrainian intelligence assessment and an unnamed Western official, that said there was information indicating that North Korea was planning to send 25,000 to 30,000 troops to Russia.

Such a new tranche of fighters would more than triple North Korea's infantry presence in the war, up from its initial batch of about 11,000 soldiers who fought for Russia in Kursk. Western estimates say 6,000 of those North Korean troops were killed or wounded.

The Japan Times, however, reported on Sunday that Ukraine's intelligence directorate (GUR) said it had "no information" about Pyongyang's plans to increase its troop count in Russia to 30,000.

GUR's press team did not respond to a request for comment sent outside regular business hours by Business Insider.

A more likely expansion is the 6,000 extra personnel Sergei Shoigu, the secretary of Russia's security council, said North Korea had pledged to Kursk.

In June, Shoigu said at least 1,000 of these people would be sappers, while another 5,000 would help with construction.

Meanwhile, top Russian officials have been traveling frequently to meet with Kim. According to Russian media, Shoigu visited Kim at least three times in three months in early summer.

The partnership between the two increasingly isolated nations has worried both South Korea and the West. Seoul's intelligence arm said on Sunday that it believed Pyongyang had already supplied Russia with some 12 million 152mm artillery shells, which could fill roughly 28,000 shipping containers.

By comparison, the US said in March that it has sent Ukraine roughly 3 million 155mm shells since the start of the war in 2022.

In return for his troops, ammunition, and weapons, Kim's government has been reported to be receiving food, cash, battlefield experience, and technological assistance for its space and arms programs.