The U.S., which stations over 28,000 troops in South Korea, has joined its ally in their annual Freedom Shield exercise to strengthen interoperability with an eye on the North. Pyongyang fired multiple ballistic missiles in apparent warning as the drills kicked off Monday. It was the North Korean missile launch of 2025.

"South Korean military has increased surveillance and maintaining readiness posture in close cooperation with the U.S.," South Korea's Joint Chiefs said on Monday.