The U.S. Department of Defense reportedly said Monday that North Korean troops have engaged in combat against Ukraine in Russia’s Kursk region and appear to have suffered casualties. 

According to Reuters, Pentagon spokesperson Patrick Ryder told reporters that the U.S. believes North Korean soldiers have engaged in combat in Kursk and has indications that some have been killed and others wounded.

It marks the first time that U.S. authorities have confirmed that the North Korean troops have engaged in combat and suffered casualties. 

The spokesperson, however, said he has no details on the number of casualties. 

North Korea has deployed about ten-thousand troops to Russia for its war against Ukraine.