South Korea’s spy agency said on Thursday that North Korea appears to have sent additional troops to Russia, after its soldiers deployed on the Russian-Ukraine fronts suffered heavy casualties. The National Intelligence Service (NIS) said it was trying to determine exactly how many more troops North Korea has deployed to Russia.

The NIS also assessed that North Korean troops were redeployed at fronts in Russia’s Kursk region in the first week of February, following a reported temporary withdrawal from the area. Ukrainian President Volodymyr Zelensky, in an address on February 7, confirmed a new Ukrainian offensive in Kursk and said North Korean troops were fighting alongside Russian forces there.