Republican chair warns Trump over South Korea’s China ties

The Republican chair of the congressional committee has urged the Trump administration to scrutinize South Korea’s close ties with China, with a warning of posing significant risks to the United States.

Representative John Moolenaar sent a letter to Secretary of State Marco Rubio in which he calls for putting Seoul-China’s relation for "heightened vigilance.”

The committee chair’s concerns stem from their deeper-level relation, Seoul semiconductor investment in China.

Although Moolenaar described Korea as a major ally of the US, he warned of “the potential for frictions to develop into a structural shift in Seoul's alignment requiring close monitoring and, as necessary, concerted action."

He warned that South Korean chip investments in China, such as Samsung's plant in Xi'an and SK Hynix's facilities in Wuxi and Dalian, could give Beijing leverage over allied technology supply chains.

The US lawmaker criticized South Korean regulators for allegedly treating Chinese e-commerce platforms like AliExpress and Temu more leniently regarding data privacy and consumer protection compared to discriminatory enforcement and heavy fines faced by American firms like Coupang.

The South Korean foreign ministry did not comment on the content of the letter while reaffirming the South Korea-US alliance as a cornerstone of its foreign policy. It also denied any allegation regarding biased attitudes towards US firms.

The letter comes as the Trump administration was already critical of the Seoul administration over its lack of support for the Iran conflict.

Despite that both countries are deepening strategic ties in economic and investment domains via use of South Korea's strategic investment fund for major US projects.

Chinese President Xi Jinping visited South Korea in 2025 and South Korean President Lee Jae Myung made a visit to China in early 2026.