South Korea has complained to the World Trade Organization (WTO) about Chinese retaliation against South Korean companies over the deployment of a U.S. anti-missile defense system in the South. South Korea and the United States say the sole purpose of the Terminal High Altitude Area Defense (THAAD) system is to guard against missile launches from North Korea, but China says that its powerful radar could penetrate into its territory and endanger its security. “We have notified the WTO that China may be in violation of some trade agreements,” South Korean Trade Minister Joo Hyung-hwan told parliament in response to questions about China’s reaction. It would be up to South Korea to follow up on its complaint to the WTO for any action to take place, analysts say, either by continuing to raise its concerns and spelling out what China is doing wrong, or by launching a trade dispute. The first step would be to formally “request consultations” with China. China is South Korea’s largest trading partner and the dispute over THAAD has resulted in a sharp decline in Chinese tourists visiting the South’s shopping districts. Chinese authorities have also closed nearly two dozen retail stores of South Korea’s Lotte Group, although Beijing has never explicitly linked the restrictions to the THAAD deployment. China’s Ministry of Foreign Affairs said it supports normal business and other exchanges between China and South Korea, the South China Morning Post reports.