South Korea and the United States on Monday began their annual two-week joint military exercise, according to the two countries' Combined Forces Command.
The exercise, Ulchi Freedom Guardian, is scheduled to last 12 days.
Yonhap News Agency said the exercise mobilizes about 50,000 South Korean forces and approximately 30,000 U.S. servicemen, including some 3,000 from the mainland and other bases in the Pacific region.
It is intended to examine the combined forces' ability to ensure security on the Korean Peninsula and maintain the joint defense capacities between the two allies.
The training is expected to include defense drills against North Korean provocations and cyber attacks that target the military network as well as contingencies involving weapons of mass destruction.
Meanwhile, President Park Geun Hye convened a National Security Council meeting Monday in conjunction with the start of the joint military exercise.
"Preparing for national contingencies is the most essential part for national security and the safety of the people," Park said during the meeting held at the presidential office, according to Yonhap.
"We cannot be negligent on that even for a moment," she told attendants at the meeting. Top-ranking officials responsible for national security attended Monday's meeting.