The Ukrainian military has revealed what it claims are intercepted radio communications between North Korean soldiers in the Russian territory of Kursk.

The audio file, shared by the Defence Intelligence of Ukraine, features a male voice saying Korean words such as “wait” and “Seal two, one, one.”

Ukraine interpreted the messages as containing an immediate order to return.

According to Ukrainian and U.S. officials, around eleven-thousand North Korean troops have been deployed to support Russia’s war in Ukraine and are currently stationed in Kursk.