The Terminal High Altitude Area Defense (THAAD) system. Thomson Reuters President Donald Trump hinted at stipulations for the US deployment of the Terminal High Altitude Area Defense (THAAD) system that is being activated in South Korea.

Trump said that he wanted South Korea to pay for the anti-missile defense system, which he estimates to cost $1 billion, and also intended to renegotiate or terminate a free-trade pact with the country because of a "deep trade decificit," Reuters reported.

When asked when he planned on renegotiating the "horrible" trade agreement, he said, "Very soon. I'm announcing it now."

However, South Korea's defense ministry rebuffed Trump's remarks, saying that there was no shift in the "basic position" and that the US should pay the cost of installing and operating the THAAD, as stated in the Status of Forces Agreement, Yonhap News reported on Friday. The defense ministry reiterated that South Korea merely provides land and supporting facilities for the THAAD.

The controversial defense system has been met with opposition not only in South Korea, but in neighboring North Korea and China as well. Several key South Korean politicians view the THAAD not as a defensive measure for their country, but as a liability for further provocations and a step back from a possible reunification with North Korea. China, on the other hand, worries that it would destabilize regional security, based upon the reported 2,000 km (1,200 mile) range of the THAAD.

The system is expected to be operational "within days."