North Korea sent an additional 1,500 troops to Russia, South Korea’s intelligence agency told lawmakers Wednesday, with around 10,000 soldiers total expected to be deployed by December.

The latest deployment brings the number of North Korean troops in Russia to 3,000, lawmaker Park Sun-won said after the National Intelligence Service (NIS) gave a briefing.

“An additional 1,500 troops are believed to have been deployed to Russia… so approximately 3,000 North Korean soldiers are believed to have been deployed to Russia so far,” Park, who sits on parliament’s intelligence committee, told reporters.

“The planned deployment of about 10,000 troops from North Korea to Russia is expected by December,” he said.

Last week, the NIS revealed that Pyongyang decided to send a “large-scale” troop deployment to help Russia in its war against Ukraine. Neither Russia nor North Korea have commented on the alleged troop deployments.

The United States and NATO have yet to confirm the deployment, but Ukrainian media reported President Volodymyr Zelensky saying Tuesday that two North Korean brigades were undergoing training in Russia.

Another South Korean lawmaker said Wednesday that the NIS confirmed the Russian military “is actively recruiting a large number of Korean language interpreters.”

North troops are being provided “with training on the use of military equipment, including drone operation and other technical skills,” lawmaker Lee Seong-kweun told reporters.

“Russian instructors participating in military training have assessed that while the North Korean soldiers display excellent physical stamina and morale, they lack sufficient understanding of modern warfare tactics, especially drone-based attacks,” Lee said.

As a result, the Russian instructors expect “there could be a significant number of casualties if North Korean forces are deployed to the frontlines,” the lawmaker added.

Experts believe North Korean leader Kim Jong Un likely hopes to acquire military technologies, such as surveillance satellites, in exchange for sending soldiers to help Russia.