Seoul’s foreign ministry summoned the Russian ambassador to South Korea on Monday to protest the deployment of North Korean troops to assist Russia’s war against Ukraine.

According to the foreign ministry, First Vice Foreign Minister Kim Hong-kyun delivered the government’s position on the matter to Russia’s top envoy to Seoul, Georgy Zinoviev, calling for the immediate withdrawal of the troops as well as the suspension of related agreements.

The ministry said Kim protested the illegal military cooperation between Pyongyang and Moscow in the strongest possible terms. 

He also warned that South Korea will respond to activities that threaten its key security interests by mobilizing all means available, together with the international community. 

Zinoviev said he listened to the South Korean government’s position attentively and will report it to Moscow.

The South Korean government is said to be discussing various measures, including independent sanctions and the deployment of lethal weapons to Ukraine.