South Korea and the United States have agreed to establish a combined division of their troops next year that will be tasked with carrying out wartime operations, Seoul's defense ministry said Thursday.

The unit, slated to be organized in the first half of next year, will be comprised of the U.S. 2nd Infantry Division and a South Korean brigade-level unit, according to the ministry.

The 2nd Division commander plans to head the newly-made joint staff of the combined unit, with South Korea's brigadier general-level officer to be its vice chief, the ministry said, adding that an equal number of dozens of service personnel from the two sides will form the leadership.

"While being operated in a separate fashion in peacetime, the 2nd Division and the Korean brigade will carry out joint exercises when necessary," a ministry official said, asking not to be named.

In time of war, the two entities will get together to carry out diverse "strategic operations" such as eliminating weapons of mass destruction as well as civil missions against North Korea, he noted, without elaborating further.

"The joint division is expected to improve the Seoul-Washington deterrence posture by proactively carrying out joint exercises.

More chances for our servicepersons to experience such joint operations will also lead to the improvement of our military's combat capabilities," according to the official.

The agreement, however, does not mean any revision to their ongoing plan of relocating the U.S. Forces Korea bases south of Seoul, according to officials.

"The 2nd Division and the headquarters of the envisioned joint unit will be based in Uijeongbu, north of Seoul. After the relocation project is completed, they will then be moved to Pyeongtaek altogether," the ministry said.

In accordance with the 2004 agreement, Seoul and Washington have been working to relocate the Yongsan Garrison, the sprawling U.S. military headquarters in central Seoul, and the 2nd Division north of Seoul to Camp Humphreys in Pyeongtaek, some 70 kilometers south of the capital, by the end of 2016.

There has long been speculation that the reorganization of the 2nd Division aims to allow some American soldiers to remain north of the capital, an option facing strong opposition from local residents.

Last year, USFK commander Gen. Curtis Scaparrotti said, "In terms of the residual in what we call Area One, there may be a need operationally to leave some residual in those areas just for proper defense and response." Area One includes the northern towns of Uijeongbu and Dongducheon, Gyeonggi Province.

"As a pledge to the people and between South Korea and the U.S., the relocation plan will proceed as scheduled, and it is not affected by the organization of the combined unit in any way," defense ministry spokesman Kim Min-seok told reporters.

About 28,500 U.S. troops are currently stationed in South Korea, a legacy of the 1950-53 Korean War. (Yonhap)