South Korea and the United States officially launched a joint working group Friday to discuss the idea of deploying an advanced missile defense shield in the Northeast Asian country, the Defense Ministry here said.

The joint group is scheduled to hold its inaugural meeting later in the day at the Ministry of National Defense. The sides are co-headed by the South Korean ministry's Director General Maj. Gen. Jang Kyung-soo and U.S. Forces Korea's Maj. Gen. Robert Hedelund.

After years of speculation over the local deployment of the U.S.-built Terminal High Altitude Area Defense, or THAAD, the allies announced last month that they will start discussing the U.S.-proposed deployment of the defense system in South Korea to better counter North Korea's growing missile threats.

Friday's official talks were launched after the two sides signed terms of reference in forming the joint working group earlier in the day.

The working level body will discuss an array of issues, including the military effectiveness of THAAD, appropriate sites for the deployment, timeline, cost-sharing, and the impact on safety and the environment, the ministry said.

"North Korea has continued its nuclear tests and long-range missile provocations and defied South Korea and the international community's deterrence efforts," the ministry said on the background of the deployment talks.

"The THAAD system to be operated by USFK will contribute to the defense of South Korea from North Korea's increasing nuclear and missile threats," it also said.

North Korea demonstrated its growing nuclear and missile capabilities with its fourth nuclear test on Jan. 6, which the communist country said was of a hydrogen bomb.

On Feb. 7, it launched a long-range rocket to put a satellite into orbit, but the outside world regarded it as a cover for testing its intercontinental ballistic missile technology.

The allies unveiled the deployment plan hours after the latest North Korean long-range rocket launch last month.

The military has said the allies are seeking to deploy one THAAD battery "at the earliest time possible," which is made up of a fire control unit, high-tech radar, six mobile launchers and 48 interceptor missiles.

Inside South Korea, the deployment is highly controversial.

Tentative candidate cities for hosting the defense system voiced opposition to deploying it to their neighborhoods, citing safety concerns involving electromagnetic wave emissions from the radar.

China has shown explicit irritation over the missile interceptor to be operated by U.S. forces in South Korea, which they say could spy on China's military posture.

The allies had postponed the joint working group's launch, which was initially set for Feb. 23. (Yonhap)