"We solemnly object to South Korea and the US' deployment of THAAD and will resolutely take necessary actions in order to safeguard our security interests," Chinese foreign ministry spokesman Geng Shuang said in a briefing. 

"Any consequences to follow the necessary actions should be bore by South Korea and the US," he said, without specifying the actions. "We strongly demand that the parties halt the THAAD deployment process immediately and not deviate to the wrong path any further."

Further escalating economic retaliations, China virtually banned its travel agencies last week from selling tour packages to South Korea while the Chinese boycott of South Korean goods is targeting South Korean retail giant Lotte Group's Chinese units.

The Chinese spokesman, however, denied any Chinese government involvement. "(China) welcomes any foreign companies including South Korean firms willing to invest and do business in China.

Their interests will be protected in accordance with the law," he said.

"Any steps China takes is taken in accordance with the law," he added. 

The same day, South Korea's foreign ministry said it will closely monitor China's retaliatory actions for possible referral to international courts.

"(Seoul) will step up its monitoring of related steps in China ... and come up with the necessary response in order to minimize damage on our side," South Korean foreign ministry spokesman Cho June-hyuck said.

"We will take steps under the international law over (Chinese) measures that are in violation of the World Trade Organization and the South Korea-China free trade agreement," Cho said. "Currently a review of legal procedures under the WTO and the FTA is under way in collaboration with other related government ministries." (Yonhap)