The US, Japan and South Korea kicked off a trilateral missile defense exercise in the East Sea on Monday.
The exercise included the ROKS Yulgok Yi I from South Korea, the USS Benfold from the United States and the JS Atago from Japan, all of which are equipped with the Aegis Combat System.
Aegis is an advanced command and control system that uses powerful radar and computers to track and guide weapons to moving targets.
During the exercise, they practiced detecting and tracking a computer-simulated ballistic missile, as well as sharing information.