The admission comes just days after Moscow confirmed the North's participation, while Russian President Vladimir Putin on Monday heralded the "feat" of Pyongyang's troops.

South Korean and Western intelligence agencies have long reported that Pyongyang sent more than 10,000 soldiers to help in Kursk last year.

North Korean forces "participated in the operations for liberating the Kursk areas", Pyongyang's Central Military Commission said in the KCNA report.

North Korean leader Kim Jong Un's decision to deploy the troops, it said, was in accordance with a mutual defence treaty.

"They who fought for justice are all heroes and representatives of the honour of the motherland," Kim said, according to KCNA.

Kim added that a monument to the "battle feats" would soon be built in the capital, and referred to "the tombstones of the fallen soldiers", publicly confirming that North Korean troops had been killed in combat.

The country must "take important national measures to specially honour and care for the families of war veterans", said Kim.

Russia's president praised Moscow's "Korean friends" for their backing in Kursk.

"We appreciate it a lot and are deeply grateful to comrade Kim Jong Un personally... and the North Korean people," the Kremlin cited Putin as saying.

Russian Chief of Staff Valery Gerasimov on Saturday said North Korean soldiers "provided significant assistance in defeating the group of Ukrainian armed forces".

South Korea's Ministry of Defence on Monday said Pyongyang "has admitted to its own criminal acts" which violate UN Security Council resolutions.

China, North Korea's key economic benefactor which has repeatedly condemned Western backing for Ukraine, declined to comment specifically on the admission from Pyongyang.

"China's position on the Ukraine crisis issue is consistent and clear," foreign ministry spokesman Guo Jiakun said.

- 'Ease internal backlash' -

Analysts believe the decision to publicly disclose the deployment had been agreed on in advance by North Korea and Russia.

"They judged that the benefits of compensation for the troop deployment outweighed the potential damage to their international image," said Yang Moo-jin, president of the University of North Korean Studies in Seoul.

By promising state benefits to the deployed troops, North Korea could also "sufficiently ease internal backlash," he told AFP.

"North Korea likely aimed to showcase that victory was achieved thanks to their involvement, thereby securing greater rewards from Russia," Yang added.

Despite Moscow claiming the "liberation" of its western region, Ukrainian President Volodymyr Zelensky said Sunday his military was still fighting in Kursk.

"The question now is whether Kim Jong Un will attend Russia's Victory Day celebrations on May 9," said Lim Eul-chul, a professor at Seoul's Institute for Far Eastern Studies.

Russia has pledged to hold its largest-ever Victory Day commemorations to mark 80 years since the defeat of Nazi Germany, featuring a massive military parade and an address from Putin.

"While the likelihood of Kim attending the event appears relatively low, it cannot be entirely ruled out," said Lim.

burs-hs-oho/rsc