Ukrainian President Volodymyr Zelenskyy says his forces may soon be facing a new enemy. He expects troops from North Korea to appear in "combat zones" as early as Sunday.

Ukraine, the US and other Western countries have said they have evidence that the North has already sent thousands of troops to Russia.

On Friday, Zelenskyy posted on X that he was briefed by a top commander about how those personnel will be used. He warned that their involvement "should not be met with indifference or uncertain commentary, but with tangible pressure on both Moscow and Pyongyang."

The North Korean foreign ministry issued a statement through the state-run news agency saying any decision to send troops would be in line with international law. It stressed that the ministry "does not directly engage" in the issue and "does not feel the need to confirm it separately."

Authorities in South Korea said on Thursday they are sending a delegation to Belgium early next week to share information with NATO and the European Union. The visit will include senior officials from the National Intelligence Service and the defense and foreign ministries.

South Korea has not supplied lethal weapons to Ukraine. However, President Yoon Suk-yeol said on Thursday that, depending on moves by the North, officials will review the policy "more flexibly."