The South Korean Northwest Islands Defence Command had staged a large-scale military exercise off the west coast, near the tense maritime border in the Yellow Sea.
Yonhap News Agency quoted battalion commander lieutenant major Lee Young-gyun as saying, "This exercise is aimed at improving the Northwest Islands Defence Command's defence posture against provocations and all-out warfare."
The exercise involved thousands of troops from the army, navy, marine corps and air force that trained under simulated battle conditions.
South Korean Army's AH-1S Cobra helicopters and air force KF-16 fighters were deployed to practice response to North Korean artillery firing.
During the 43rd annual Security Consultative Meeting (SCM), the South Korean Defence Minister Kim Kwan-jin and US Defence Secretary Leon Panetta agreed to complete a joint operational plan, the South Korea-US Counter-Provocation Plan, this year.