“Today, we already have preliminary data that the Russians have begun to use North Korean soldiers in their assaults. A significant number of them,” said Zelensky in his evening address. “The Russians include them in combined units and use them in operations in the Kursk region,” he said.

While so far they had only been deployed there, they might also be sent to other parts of the frontline, he said, adding: “There are also already noticeable losses in this category.”

Taken by surprise by the Kursk incursion, Russia has since steadily clawed back territory, halting Ukraine’s advance and rushing reinforcements to the region. A Ukrainian army source told AFP last month that Kyiv still controlled 800 square kilometres (300 square miles) of the Kursk region, down from previous claims it controlled almost 1,400 square kilometres.