North Korea recently sent some 3,500 additional soldiers to Russia’s Far East for field training, a South Korean lawmaker said Wednesday, with the possibility of a third wave of troops soon being dispatched to the frontlines of Moscow’s war against Ukraine.

Rep. Yu Yong-weon of the ruling People Power Party outlined the developments in a statement posted on Facebook, citing a briefing from Ukrainian defense intelligence chief Lt. Gen. Kyrylo Budanov during his visit to the country on Feb. 23-26.

Yu said the North sent roughly 12,000 troops to Russia in October and deployed additional forces in January and February, with a second wave of 1,500 soldiers already sent to the frontlines in Russia’s Kursk region after undergoing local adaptation training.