Blinken and Secretary of Defense Lloyd Austin co-hosted South Korean Foreign Minister Cho Tae-yul and Defense Minister Kim Yong-hyun in Washington on Thursday to discuss pressing security threats as they closely monitor North Korea's deployment of thousands of troops to Russia.
Ukraine and its allies expect they will be deployed to assist Moscow's war effort.
Ukrainian President Volodymyr Zelensky, speaking to South Korean media this week, denounced what he called inaction by his Western allies on the issue of North Korean troop deployments.
With thousands of North Korean troops deployed to Russia for likely action against Ukraine, there are looming questions over how well the fighters, who lack combat experience, will perform.