Washington has revoked TSMC’s fast-track approval for exporting U.S. chipmaking equipment to its main plant in Nanjing, China, a step taken just days after similar action against South Korea’s Samsung and SK Hynix. The decision reflects U.S. efforts to limit China’s access to advanced American technology. Until now, TSMC and its rivals had exemptions under the “validated end user” status, which allowed them to bypass broad export restrictions. That privilege will expire on December 31, meaning TSMC will need U.S. licenses to ship equipment to its China facility.

The Nanjing plant makes 16-nanometre and other older-generation chips, not TSMC’s most advanced semiconductors, and accounted for about 2.4% of revenue last year. TSMC said it is assessing the situation, in talks with U.S. authorities, and committed to keeping the plant running smoothly. Taiwan’s Ministry of Economic Affairs also pledged to work closely with both Washington and TSMC.

The U.S. Commerce Department noted it would continue granting licenses for companies to run existing operations in China but not to expand or upgrade them. Shares of Samsung and SK Hynix dropped after their exemptions were removed, while TSMC stock was largely unchanged. The rule change could reduce sales for U.S. equipment suppliers like KLA, Lam Research, and Applied Materials. However, analysts said Chinese toolmakers are unlikely to gain, since major expansion projects are already complete. Instead, Chinese component suppliers may benefit by providing parts and maintenance for imported machines.