South Korea and the United States have begun their annual joint military exercises under the threat of military retaliation by North Korea.
About 25,000 U.S. forces and 50,000 South Korean troops are involved in the two-week Operation Ulchi Freedom exercise, which is largely simulated.
Pentagon spokesman Navy Captain Jeff Davis told VOA on Monday that the drills are designed to make sure the United States can honor obligations to defend South Korea "against any potential aggression from the North."
"This is an exercise we do every year," Davis said. "It is 100 percent defensive in nature."
'Joint and Combined Exercise'
The drills are a "joint and combined exercise" that involves different capabilities across different branches of the military, Lt. Gen. Stephen Lanza, who commands the Army's I Corps on the U.S. Pacific coast, said Monday.
Speaking to VOA from Joint Base Lewis McChord in Washington state, Lanza said the U.S. Army's role in this year's exercise is set apart from previous years because soldiers are carrying out distributed mission commands, covering great distances and multiple time zones during the drills.
Forces in the main command post on the continental U.S. will be operating simultaneously with forces in the U.S. state of Hawaii, in Japan and in Korea.
"We're executing mission command at every echelon," Lanza said. "We have not done that recently for a large exercise."
The troops will practice a wide variety of war-fighting functions, running through sustainment activities and even transitioning a battlefield surveillance brigade forward to practice intelligence sharing with the South Koreans.
"We're training for things we would do as part of our wartime mission," the general told VOA.
The drills routinely anger Pyongyang, which says it sees the exercises as a rehearsal for a full-scale invasion of the North.
A statement issued Monday by the North's military said its first-strike units were ready to turn the United States and Washington "into a heap of ashes through a Korean-style preemptive nuclear strike," if North Korea's sovereignty is threatened.
Tensions on the Korean peninsula have worsened in recent months, with North Korea under harsh U.N. sanctions over a series of tests of its nuclear weapons and ballistic missiles.
Relations are also likely aggravated by the recent defection of a high-ranking diplomat, Thae Yong Ho; Pyongyang's deputy ambassador to Britain. The North denounced Thae as "human scum" and accused him of a number of criminal acts, including child molestation.
South Korean President Park Geun-hye told her National Security Council on Monday that Thae's defection was a sign of "serious cracks" in North Korea's ruling elites.
North and South Korea technically remain under a state of war dating from the 1950-'53 civil war that ended with a truce rather than a peace treaty. South Korean Unification Ministry spokesman Jeong Joon-hee said Pyongyang is “distorting” the exercises.
"We express strong regret toward North Korea for distorting the fact and denouncing our annual defensive exercise as a ‘nuclear first-strike’ and ‘invasion of North Korea,'" Joon-hee said. "Also, we define Pyongyang's acts of threatening us with a ‘nuclear first-strike attack’ and making such highly threatening remarks as regretful acts that should not be made."