South Korea, the United States and Japan held a joint missile defense exercise in open waters of the East Sea on Wednesday to counter North Korea's growing missile threats. 

South Korea's Joint Chiefs of Staff(JCS) said the three nations staged the drills from 9 a.m. to 2 p.m. in international waters of the East Sea. 

According to the JCS, the exercise mobilized three Aegis-equipped destroyers -- South Korea's Sejong the Great, the U.S.' USS Barry and the Japan Maritime Self-Defense Force's JS Atago.

The three sides reportedly focused on practicing procedures to detect, track and intercept computer-simulated targets while sharing information. 

The JCS said the nations strengthened security cooperation and further enhanced response systems through the maritime missile defense exercise.