President Volodymyr Zelenskyy said Tuesday that Ukrainian troops captured two Chinese citizens fighting alongside Russian forces, adding that Kyiv would demand an explanation from Beijing and a reaction from its allies.

Moscow and Beijing have deepened political, military and economic cooperation since Russia invaded Ukraine in February 2022.

"Our military captured two Chinese citizens who fought in the Russian army. This happened on the territory of Ukraine — in the Donetsk region," Zelenskyy said in a post on social media.

"We have the documents of these prisoners, bank cards, and personal data," Zelenskyy said in a post that included a video of one of the alleged Chinese prisoners.

There was no immediate response to the claims from Moscow or Beijing.

China presents itself as a neutral party in the conflict and says it is not sending lethal assistance to either side, unlike the United States and other Western nations.

But it is a close political and economic ally of Russia and NATO members have branded Beijing a "decisive enabler" of Moscow's invasion, which it has never condemned.

U.S. President Donald Trump has been pushing for a speedy end to the more than three-year war since taking office but his administration has failed to reach a breakthrough despite rounds of negotiations.

Kyiv has repeatedly urged Beijing to pressure Moscow to end its invasion that has cost tens of thousands of lives and yet still so far failed to see the Kremlin achieve its core objectives.

Zelenskyy said Kyiv had evidence that "many more Chinese citizens" are fighting alongside Russian forces.

"I have instructed the foreign minister of Ukraine to immediately contact Beijing and find out how China is going to respond to this," Zelenskyy said.

He said the capture of the two men and Moscow's involvement of China in the conflict were "a clear signal that Putin is going to do anything but end the war."

Zelenskyy also demanded "a reaction from the United States, Europe, and everyone in the world who wants peace" in his post online.

"I think the United States should pay more attention to what is happening today," he said separately at a press conference in Kyiv.

Ukraine has been urging its Western partners to respond to the Russian deployment of thousands of North Korean troops to the western region of Kursk.

Ukraine has been struggling to hold ground after launching an offensive on the border region last year.

"The North Koreans fought against us in the Kursk region, the Chinese are fighting on the territory of Ukraine. And I think this is an important point that we need to discuss with our partners, I think urgently," Zelenskyy said in the press conference.

Kyiv, which dispatched its then-foreign minister Dmytro Kuleba to China last year, has been seeking to deepen ties with Beijing, and Zelenskyy this week appointed a new ambassador to China.