Several Ukrainian sources have been claiming North Korean involvement in the war, with Ukrainian President Volodymyr Zelensky making the accusation on Wednesday without providing specifics.

“The coalition of criminals together with Putin currently includes North Korea — the Kim family, which enslaves more than 20 million of the Korean people. Our intelligence records not only the transfer of weapons from North Korea to Russia but also the transfer of people,” he said during a speech to the Ukrainian Rada, presenting his so-called victory plan.

“These are workers for Russian factories, instead of Russians killed in the war, and personnel for the Russian army. This is the participation of the second state in the war against Ukraine on the side of Russia,” Zelensky added.

He went so far as to say that Ukraine was at war with three countries: Russia, Iran, and North Korea.

United States Deputy Secretary of State Kurt Campbell said the U.S. couldn’t confirm Ukraine’s claim of direct North Korean involvement. NATO Secretary General Mark Rutte also said the alliance couldn’t confirm the claims at a briefing on Wednesday.

The Washington Post, the Guardian, and several Ukrainian sources have all claimed the involvement, to varying degrees, of North Korean soldiers in Ukraine. Most disagree over the extent of involvement, with each giving different figures and details.

Last week, a Washington Post report, citing an anonymous Ukrainian intelligence official, claimed that “several thousand” North Korean troops were training in Russia and could be deployed to the front line in Ukraine as early as this year. The North Korean soldiers who are on the ground are only there as observers, he said, with none seeing direct combat yet.

An anonymous Western diplomat told the Kyiv Independent that North Korea had sent 10,000 soldiers, though their roles were unclear.

A Russian dissident Telegram channel claimed that six North Korean officers were killed in a Ukrainian missile strike in Donetsk, a claim boosted by a Ukrainian official. He said that the soldiers “did not directly participate in combat, but they were military personnel already integrated.”

The most direct claim is from Ukrainska Pravda, which, citing unnamed special services sources, claimed that Russia was assembling a 3,000-strong force known as the “Buryat Battalion.” Buryats are a Siberian ethnic group of Mongolian origin who have become renowned for their fighting ability in Russia and alleged brutality in Ukraine. They feature heavily as the targets of derision in Ukrainian media and nationalistic music.

South Korean Defense Minister Kim Yong-hyun said the reports of direct North Korean military involvement were “highly likely,” though his evidence was circumstantial.

“Russia and North Korea have an agreement that is basically a military alliance, so it is highly likely that North Korea would send additional troops,” he told lawmakers. “That’s how we’re assessing it, and we will definitely prepare for it.”

Kremlin spokesman Dmitry Peskov dismissed claims of North Korean involvement as “fake news.”

Some Russian Telegram channels mocked the claims.

“Real stealth soldiers. Everyone talks about the Koreans, but no one has seen them,” the Wagner-linked Reverse Side of the Medal channel quipped.

North Korea has one of the largest standing armies on Earth, with nearly 1.3 million active personnel and 600,000 reservists. However, its quality has come under question, wielding largely outdated Soviet-era equipment. The crippling poverty and dire living standards of the country have also brought into question the soldiers’ morale.

Nevertheless, some Russian and Ukrainian sources agree that the soldiers could be used to man inactive parts of the front line(s) in order to open up Russian troops for operations elsewhere.

Eul-Chul Lim, a professor at the Institute for Far Eastern Studies in Seoul, told AFP that North Korea could see the war in Ukraine as an opportunity to give its military “real-world combat experience.”

“This might even be a driving factor behind sending North Korean soldiers — to provide them with diverse experiences and wartime training,” he said.

Russia and North Korea have grown increasingly close following the former’s invasion of Ukraine in February 2022, with Pyongyang providing large amounts of war material for the Russian war effort, especially shells.