The U.S. Defense Department said Thursday that the THAAD missile defense system to be deployed to South Korea won't be directed towards any third party nations, other than defending against nuclear and missile threats from North Korea.

South Korea and the U.S. announced earlier that they have officially decided to deploy a Terminal High Altitude Area Defense battery in South Korea to cope with ever-growing nuclear and missile threats from the communist nation.

"When the THAAD system is deployed to the Korean Peninsula, it will be focused solely on North Korean nuclear and missile threats and would not be directed towards any third party nations," the Pentagon said in a statement, apparently referring to China and Russia.

Beijing and Moscow have voiced strong opposition to THAAD placement in the South, claiming that the system, especially the powerful X-band radar that comes with THAAD, could be used against them, despite repeated assurances from Washington that it's a purely defensive system designed solely for countering the North Korean threats.

The Pentagon said that the North's nuclear test and multiple ballistic missile tests, including the recent intermediate-range ballistic missile launches, "highlight the grave threat that North Korea poses to the security and stability of the Republic of Korea and the entire Asia-Pacific region."

It stressed that the decision to deploy THAAD came "as a defensive measure to ensure the security of the ROK and its people, and to protect alliance military forces from North Korea's weapons of mass destruction and ballistic missile threats."

"Through the past months of review, the ROK-U.S. Joint Working Group confirmed the military effectiveness of THAAD on the Korean Peninsula and is in the final stage of preparing its recommendation for both the ROK minister of national defense and the U.S. secretary of defense regarding the optimal site in the Republic of Korea for the system's effectiveness and for environmental, health, and safety requirements," the Pentagon said.

It also said that the THAAD deployment will contribute to "a layered missile defense that will enhance the alliance's existing missile defense capabilities against North Korean missile threats."

The two countries are also working closely together to ensure the swift deployment of THAAD and will develop specific operational procedures, the Pentagon said. (Yonhap)