In response to North Korea's growing missile threat, the United States, South Korea and Japan held a three-way missile defense exercise in the East Sea on Monday.
The South Korean Navy said it was an effort to improve security cooperation and better respond to threats from Pyongyang.
Tensions have escalated in recent weeks following increased military activity by North Korea, prompting a warning to Japan following its ballistic missile test.
The exercise brought together the South Korean 7,600-ton Aegis destroyer Yulgok Yi I, the US guided-missile destroyer Benfold, and the Japanese Atago destroyer, also equipped with the Aegis radar system.
The effort focused on mastering response procedures, including detection, tracking and information sharing by creating virtual targets in scenarios featuring South Korean ballistic missiles.
Earlier, the three countries had promised to hold regular missile defense and anti-submarine exercises in an effort to improve diplomatic and military cooperation.
