South Korea and the U.S. began their annual Ulchi-Freedom Guardian(UFG) joint military exercise on Monday amid heightened tensions on the Korean Peninsula.
The UFG exercise, which will run through to the end of the month, largely consists of computer simulation-based drills aimed at evaluating and improving combined military procedures.
The drills will be based on the bilateral Operations Plan 5015 and joint deterrence strategies.
The UFG has been held since 2008, combining the government's Ulchi exercise and the military's Freedom Guardian exercise.
The Ulchi drill was first conducted in July 1968 following a North Korean attack on South Korea's presidential office in January that year.
Freedom Guardian is the annual South Korea-U.S. defense drill that was formerly called the Ulchi Focus Lens. It changed its name in 2007. The new name also marked a reverse in the roles of the two countries' militaries with South Korea taking the lead under U.S. support.
This year's Ulchi exercise was held Monday to Thursday with the participation of some 480-thousand personnel of 4,000 administrative or public agencies and organizations.
Meanwhile, 50-thousand South Korean troops and some 17-thousand-500 U.S. military personnel are taking part in the Freedom Guardian joint exercise.
Some 75-hundred fewer U.S. troops are taking part this year.
Seoul and Washington have in place a three-step deterrence strategy against North Korea that involves stages of Pyongyang's threat to use nuclear weapons, imminent signs of use, and actual use of nukes.
During drills, the allies will examine deterrent measures that can be mobilized at times when signs of war are detected.
The UFG is held in compliance with the inter-Korean armistice agreement.
This year, seven nations are observing the exercise - Australia, Canada, Colombia, Denmark, New Zealand, the Netherlands, and Britain.
Also in an unusual move, U.S. military commanders have also come to observe the drills.
Commander of the U.S. Pacific Command Harry Harris, U.S. Strategic Command chief John Hyten, and Samuel Greaves, Director of the U.S. Missile Defense Agency, held a joint news conference on Tuesday.
Hyten reaffirmed the U.S.’ commitment to provide all strategic assets to Seoul if they are required to deal with the threat from the North. He said all space, cyber, and deterrent capabilities the strategic command has will be provided in order to provide options to deal with various situations.
It’s highly unusual for the three commanders to visit South Korea at the same time, much less hold a joint news conference. Their visit is viewed as a strong warning to North Korea.
Pyongyang has always reacted angrily to the UFG and this year is no exception. The North has said through state media that the exercise will further aggravate the current situation, using the phrase "pouring oil on fire."
South Korea and the U.S. have bolstered alerts against a possible provocation from the North.