South Korea has begun operating this year’s first batch of domestically developed Cheongung-II medium-range surface-to-air missile (M-SAM-II) systems, strengthening the country’s lower-tier missile defense against North Korean missile threats.

Seoul’s Defense Ministry announced in a press release Monday that the first Cheongung-II battery scheduled for deployment this year entered full operational service two days earlier, after being assigned to a missile defense unit in Gyeonggi Province in May and completing simulated exercises.

The Cheongung-II system is designed to intercept ballistic missiles during the terminal flight phase at lower altitudes. It complements the U.S.-made Patriot missile defense system by providing lower-tier