U.S. Expands 301 Probe to 16 Partners, Korea Included, 15% Tariffs Possible

The United States has launched Section 301 investigations into 16 major trading partners, including South Korea, over alleged manufacturing overcapacity. Seoul’s government says, if this process leads to tariff changes, Korean goods could be subjected to roughly the 15% level that was agreed in last year’s tariff negotiations between Washington and Seoul.

Under Section 301, the USTR can respond to foreign trade practices that it deems discriminatory or otherwise unfair. The move follows a Supreme Court ruling that found certain unilateral tariffs imposed under the IEEPA were unconstitutional, prompting the Biden administration to roll out a 10% global tariff under Section 122 for 150 days. The administration then signaled a path to rebuild tariff structures through Section 301, alongside existing Section 232 measures on autos and steel.

The Trump-era framework cited in the discussion suggested that the 15% average Korea tariff target would be restored after the 301 review. While the USTR has said the probe targets a broad set of factors across 16 countries, Korea has highlighted that it would be wrong to view the action as aimed at Korea alone.

During a briefing, Yeo Han-koo, head of the Trade Negotiations Bureau at South Korea’s Ministry of Trade, Industry and Energy, stressed that the 301 investigation seeks to address structural issues affecting multiple economies. He added that Coupang is not involved in the probe, even as USTR indicated it had discussed the company’s case. Yeo also noted concerns raised about a data-privacy breach affecting a large share of Korean citizens, and he said the issue should not drive a 301 action.

The USTR opened a public comment window from March 17 to April 15, with a public hearing set for May 5. If the investigation proceeds to tariff recommendations, officials said measures could come as early as July. The plan to address 16 countries under a single 301 process is unusually rapid, and seen by Seoul as an attempt to replace the current tariff regime with a unified, 301-based approach.

U.S. officials have signaled they may expand the scope of the inquiry to topics beyond overcapacity, including digital services taxes, drug pricing, seafood and rice market access, and environmental issues such as marine pollution. They also left open the possibility of additional 301 investigations into other countries, which would widen the political and economic stakes beyond Korea.

For U.S. readers, the potential shift carries significance for supply chains and prices across American industries that rely on Korean electronics, automobiles, machinery, steel, and ships. South Korea is a major supplier of advanced components and vehicles, and any move toward higher tariffs could influence pricing, investment decisions, and the competitive dynamics of global markets. The route and speed of the 301 process will thus be watched closely by U.S. manufacturers and policymakers alike, given the broader aim of recalibrating how Washington uses tariff levers in response to perceived global overcapacity.