Ukrainian President Volodymyr Zelenskyy has issued a warning that the war with Russia may be about to enter a new phase. He says North Korean troops are likely to join the fighting in a matter of days, not months.

Zelenskyy made the comments in an interview with South Korea's public broadcaster, KBS. He denied reports that North Korean troops are already on the battlefield.

He added that Pyongyang has also sent a large number of civilians to Russia to work in military factories, such as those that produce drones, and that the North will acquire drone technology in return.

Meanwhile, Ukraine's top commander, Oleksandr Syrskyi, said he has discussed an international response to the deployment with NATO's Supreme Allied Commander Europe Christopher Cavoli. He wrote on social media that the two exchanged views on what he called an immediate and tough response.