Pyongyang has dispatched thousands of troops to fight for Moscow, according to South Korean and Western intelligence agencies, as Russia presses ahead with its nearly four-year invasion of Ukraine.

In the message, published by the state-run KCNA news agency, Kim said 2025 was a "really meaningful year" for the bilateral alliance that was consolidated by "sharing blood, life and death in the same trench."

North Korea only confirmed in April that it had deployed troops to support Russia's military campaign against Ukraine and that its soldiers had been killed in combat.

Earlier this month, Pyongyang acknowledged that it had sent troops to clear mines in Russia's Kursk region in August 2025.

At least nine troops from an engineering regiment were killed during the 120-day deployment, Kim said in a speech on December 13 marking the unit's homecoming.

Kim sent Putin his new year's greetings a day after the North Korean leader ordered officials to step up missile production.

Pyongyang has increased missile testing in recent years -- aimed, analysts say, at improving precision strike capabilities, challenging the United States as well as South Korea, and testing weapons before exporting them to Russia.

In addition to sending troops to fight for Russia, Pyongyang has sent artillery shells, missiles and long-range rocket systems.

In return, Russia is sending North Korea financial aid, military technology and food and energy supplies, analysts have said.