America’s fiercest adversaries are using the Ukraine War as a “proving ground” to train and prepare for future battles against the West, a Ukrainian commander who fought North Koreans in Kursk has warned.

“North Koreans are making progress with the information and the experience that they gain here,” said Capt. Oleh Shyriaiev, commander of Ukraine’s 225th Separate Assault Battalion.

“They are learning and they are learning it with a view of adapting this and using this on their own peninsula to train its own army in what they are learning here.”

Shyriaiev’s caution comes after as many as 155 Chinese troops were discovered fighting for Russia.

Speaking to The Post via phone from the Belgorod region of Russia where Ukraine on Tuesday confirmed they had conducted a new incursion, Shyriaiev urged that the world — and particularly Americans — must pay attention to what other adversaries are doing in Russia’s war.

“The only thing that we can predict is that this situation will be getting worse, because we know that North Korea has always had this ambition to try and take over the whole Korean peninsula, so our war is where they learn how to do that,” he said.

“This is unfortunate that my country has become a proving ground for war; that this is a ground where war is going on,” he added.

Ukrainian President Volodymyr Zelensky said Tuesday that two Chinese nationals were captured fighting for Russian forces in eastern Ukraine, but as many as six were seen fighting for Moscow with the same unit.

By Wednesday, Ukrainian intelligence had discovered as many as 155 Chinese citizens on Moscow’s military roster fighting against Kyiv, Zelensky said.

“We are collecting information and we believe that there are more, many more,” Zelensky said, noting that Russia has been running recruitment advertisements on Chinese social networks.

“These people arrive to the Russian Federation, to Moscow. Medical examinations last three to four days. Training centers are for one to two months. They fight on the territory of Ukraine,” he said.

The Chinese Foreign Ministry on Wednesday said it was “verifying” Ukraine’s reports of Chinese citizens caught fighting for Russia, who Zelensky said were discovered to have full identification, including Chinese credit cards, with them when captured.

However, Beijing denied sending troops to Ukraine under an official arrangement.

“Let me stress that the Chinese government always asks Chinese nationals to stay away from areas of armed conflict, avoid any form of involvement in armed conflict, and in particular avoid participation in any party’s military operations,” foreign ministry spokesman Lin Jian said.

But Shyriaiev said he believed the Chinese troops were sent to the fight to collect information on how modern war is being fought, as China — like North Korea — has not had on-the-ground combat experience in decades.

“I think that China is conducting some sort of research and development in this war, and their goal is also to gain practical experience,” he said. “And it is logical that it would choose Russia. Russia does not have any other option but to cooperate with these communist countries.”

However, analysts at the Washington-based Institute for the Study of War believe it is more likely that the Chinese citizens in the Russian military joined on their own without the backing of Beijing.

Still, ISW’s Russia team lead George Barros said that foreign adversaries would have a substantial interest in joining Moscow’s fight to gain on-the-ground experience in modern warfare.

“Unlike the Chinese, the North Koreans are absolutely co-belligerents with Russia in the war,” he said.

“There are officers there, there are infantrymen there, they’re learning, they’re getting technical exchanges,” he added.

Barros warned the experience could be a threat to NATO.

“Funnily enough, the North Koreans now actually have more real-life, practical experience with how to wage large-scale operations and contemporary warfare than the United States and every single country in NATO,” he said.

The fight in Ukraine is closely watched by military strategists for its unique combination of old-school tactics like trench warfare combined with modern — and terrifying — new technologies, such as ballistic drones.

“The interest that North Korea has in sending their troops to this war is to gain experience of participating in a modern war because this is the most modern war that uses the most modern technology,” the Ukrainian captain said.

North Korean troops were clearly learning from their time in Kursk, Shyriaiev said. The first time he encountered them on the battlefield, they were unfamiliar with drones and relied on traditional weaponry — and were less prepared to take on Ukraine’s modern practices.

But by the second time he faced off against North Korean troops, they were prepared for the modern fight, he said.

“We were able to hold our positions thanks to the fact that we that we have been prepared, but at that moment, they had already started waging war the way that we do, and that Russians do, meaning they were using unmanned aerial vehicles,” he said.

“They were giving support to the infantry by dropping explosives, so they are making progress,” Shyriaiev added.

“They are dressed in Russian uniforms. They are using Russian weapons. And they are they are gaining experience of waging a modern war.”