A U.S. Army brigade with some 4,500 troops will deploy to South Korea early next year as part of a regular rotation of forces, the Department of the Army announced.

The 1st Cavalry Division's 1st Armored Brigade Combat Team will replace the 2nd Armored Brigade Combat Team that was deployed in June under a decision to replace a permanent brigade, which had been stationed in South Korea since 1965, with a rotational unit.

Rotation takes place every nine months.

"The 1st Cavalry Division reflects mutual commitment between the Republic of Korea and the United States by providing continued support with a rotational force brigade to replace Black Jack brigade," Maj. Gen. Michael Bills, the commanding general of the 1st Cavalry Division, said in a statement.

"The Ironhorse brigade is ready to help maintain peace and security on the Korean Peninsula," he said.

U.S. officials have said the decision to have rotational forces, instead of a permanent unit, would increase efficiency and cohesion among members of the unit because the entire brigade will be trained, deployed and leave at the same time.

Members of the now-deactivated permanent brigade had been rotated on an individual basis.

About 28,500 American troops are stationed in South Korea to deter North Korean aggression, a legacy of the 1950-53 Korean War, which ended in a truce, not a peace treaty, leaving the divided peninsula still technically at war. (Yonhap)