U.S. congressmen said on Friday that a primary reason the U.S. needs to deploy the Terminal High-Altitude Area Defense (THAAD) system to South Korea is China’s failure to rein in the North.

"If China were doing enough to curb North Korea's misbehavior, then there would be no need for THAAD at all," Representative Jim Cooper (D-Tennessee) told the Yonhap News Agency.