The U.S. and South Korea announced on Sunday that they will start negotiations on THAAD deployment following North Korea’s launch of a satellite in defiance of international opinion, the Yonhap News Agency reported.

The U.S. has sought to convince South Korea to deploy THAAD – short for Terminal High Altitude Area Defense – a sophisticated missile defense system, for years to counteract North Korea’s weapons proliferation. South Korea has thus far weighed the U.S.’s wishes against those of China and Russia, who view THAAD deployment in a neighboring country as a threat.