Military vehicles carrying equipment pass a village on a road leading to the Terminal High Altitude Area Defense (THAAD) base in Seongju, about 220 kilometers south of Seoul, in the middle of the night, Oct. 6. Yonhap

The U.S. Forces Korea (USFK) has brought in new pieces of equipment to its THAAD missile defense unit in a southern county in a move to complete an upgrade program to enhance the efficiency of its overall anti-missile capabilities, Seoul officials said Friday.

For years, the USFK has been working on a three-stage program, called the Joint Emergent Operational Need (JEON), aimed at integrating the Terminal High Altitude Area Defense (THAAD) system and the Patriot Advanced Capability (PAC)-3 Missile Segment Enhancement system into a single defense structure.

With the delivery of the new equipment on Thursday, the program is expected to be complete by the end of this month, according to the officials.

The first stage of the program is to separate launchers from the battery to enable remote control of the launchers. The second is to allow the use of advanced THAAD radar information for the launch of Patriot missiles.

The last stage is to integrate Patriot missiles into the THAAD launchers.

The THAAD system is designed to shoot down hostile missiles at altitudes of 40-150 kilometers while the PAC-3 MSE system is to intercept missiles at altitudes of 40 km and lower. The integration of the two systems is expected to enhance operational flexibility, observers said.

Seoul's defense ministry expressed expectation that the upgrade will further strengthen national defense.

"With this upgrade of the THAAD system, the system's defense capabilities will be enhanced to protect South Korean citizens from North Korea's missile threats and further strengthen the capabilities to defend our core assets," it said in a press statement.

The ministry added that the new pieces of equipment will replace the existing ones, which will be transported back to the U.S. The remarks came amid China's opposition to any deployment of additional THAAD interceptors.

"The new equipment does not mean the deployment of an additional THAAD system," the ministry said.

A ministry official cast the upgrade as an example of the United States having delivered on its "extended deterrence" commitment to the defense of South Korea.

Extended deterrence refers to America's commitment to mobilizing a full range of its military capabilities, including nuclear options to defend its ally.

The THAAD system was installed in the southeastern county in 2017 to cope with North Korea's missile threats but its deployment has faced opposition from local residents over the potential health and environmental impact. (Yonhap)