South Korea Says Its U.S.-Made Missile Shield Is ‘Not Negotiable’ With China

South Korea said the possible operation of a controversial American-made missile shield was “not negotiable,” pushing back at China’s efforts to hold President Yoon Suk Yeol to his predecessor’s policy to freeze its deployment.

Decisions on the deployment of Lockheed Martin Corp.’s Terminal High-Altitude Area Defense system was a matter of South Korea’s self-defense, a senior presidential official told reporters Thursday in Seoul. The Yoon administration is accelerating efforts to “normalize” the operation of the US base in the southern city of Seongju that deployed the Thaad system, the official said.

China is pushing to reaffirm former South Korean President Moon Jae-in administration’s policy of not allowing additional Thaad deployments. The Moon administration made the announcement in 2017 as it aimed to resolve Chinese trade curbs imposed after the first missile-defense system was delivered as part of US-led efforts to counter North Korea’s nuclear expansion.

Yoon has pledged make the current Thaad system fully operational and install another unit in the Seoul area. China objects to the shield over concerns its powerful radar would allow spying on its own missile systems.

The missile shield represents the latest test of Yoon’s promise to strengthen security ties with the US and Japan, and take a tougher line against China and North Korea. He refused an in-person meeting with US House Speaker Nancy Pelosi in Seoul earlier this month after her visit to Taiwan and initially appeared hesitant at joining President Joe Biden’s chip alliance.

Yoon’s administration has since proposed preliminary talks with Washington on taking part in the Chip 4 grouping. He told reporters Friday that the US-South Korea partnership now “goes far beyond a security alliance, which now encompasses economic security.” He added that the alliance was “fundamental” to South Korean diplomacy.

Foreign Minister Wang Yi reiterated Beijing’s desire to maintain what it claims is an agreement with Moon during a meeting with his South Korean counterpart, Park Jin, Tuesday in Qingdao. Under the “Three Nos” policy, the Moon administration announced no additional Thaad deployments, no participation in a US-led missile-defense network and no involvement in a three-way alliance with the US and Japan.

“China attaches importance to this position of the ROK government,” Foreign Ministry spokesman Wang Wenbin told a regular news briefing Wednesday in Beijing, referring to South Korea’s formal name. “Based on the understanding between the two sides, China and the ROK were able to properly handle the Thaad issue.”

Operation of the first Thaad system has been hindered by protests near the site. The Yoon administration wants to bring the base into normal operation by the end of this month, the South Korean official said.

—With assistance from Colum Murphy