The Pentagon says it is adding 400 soldiers to its force in South Korea. They are members of an Army battalion equipped with the Multiple-Launch Rocket System, an armored vehicle that fires surface-to-surface rockets.

A Pentagon spokesman says the extra firepower and soldiers were not requested by U.S. commanders in South Korea. Rather, the additions reflect an internal Army reorganization that is increasing the number of Multiple-Launch Rocket System battalions in each field artillery brigade from two to three worldwide.

The unit deploying to South Korea on a nine-month rotation is the 2nd Battalion, 20th Field Artillery Brigade from Fort Hood, Texas.

The U.S. now has about 28,500 troops in South Korea.