President Donald Trump’s trade team has initiated broad investigations into 16 significant U.S. trading partners, laying groundwork for a possible fresh round of tariffs after the Supreme Court struck down the administration’s earlier duties last month.
U.S. Trade Representative Jamieson Greer said Wednesday, March 11, 2026, that his office will probe China, the European Union, Japan, India, South Korea, Mexico and ten other economies for allegedly sending excess manufacturing capacity into global markets. The inquiry could be used to impose new import taxes on items from steel and semiconductors to processed foods and solar panels before summer.
The action is the administration’s most forceful effort so far to revive its tariff program after a 6-3 Supreme Court ruling on February 20, 2026, that nullified President Trump’s International Emergency Economic Powers Act duties. Within days of that ruling, Trump applied a 10% global tariff under Section 122 of the Trade Act of 1974—a balance-of-payments authority he later raised to 15%. That measure, however, lasts only 150 days unless Congress votes to extend it, with expiration around July 24.
Section 301 probes provide an alternative without fixed time limits or caps on tariff levels. Greer told reporters his office intends to wrap up the investigations before the current 150-day window ends, potentially enabling the administration to keep or boost duties on major trading partners indefinitely. Treasury Secretary Scott Bessent recently forecasted that by August, U.S. tariffs would revert to pre-ruling levels.
“Our view is that key trading partners have developed production capacity that is really untethered from the market incentives of domestic and global demand,” Greer said at a press briefing.
A separate probe launched Thursday targets roughly 60 countries to determine whether foreign governments effectively ban imports of goods made with forced labor. That investigation includes Canada and the United Kingdom, neither of which was listed in the excess-capacity manufacturing inquiry.
The manufacturing inquiry focuses on economies Greer says produce far more than their populations consume, allegedly achieved via subsidies, low wages, state-owned enterprises, lax environmental enforcement, and currency manipulation. According to administration officials, those practices displace U.S. manufacturers and hinder domestic industry growth.
The probes cover 20 manufacturing sectors, including aluminum, automobiles, batteries, cement, chemicals, electronics, energy goods, glass, machine tools, machinery, paper, plastics, processed foods, robotics, satellites, semiconductors, ships, solar modules, steel, and transportation equipment. Several targeted countries recently reached trade deals with Washington, such as Indonesia, which in February secured a landmark deal removing tariffs on more than 99% of U.S. exports to that market.
Unlike the president’s earlier tariff proclamations, Section 301 proceedings include public comment windows and hearings. The Office of the U.S. Trade Representative will accept written comments through April 15, with a public hearing on manufacturing excess capacity slated to start May 5. A separate hearing on forced labor practices is scheduled for April 28.
The comment docket opens March 17, giving stakeholders exactly one month to submit feedback before the deadline. Greer has asked for formal consultations with all 16 governments named in the manufacturing probe.
Canada’s omission from the manufacturing list attracted attention, though it is included in the forced labor inquiry. The European Union appears on both lists, alongside China, Japan, India, South Korea, Vietnam, Mexico, Singapore, Switzerland, Norway, Malaysia, Cambodia, Thailand, Taiwan, Bangladesh, and Indonesia.
Greer said additional investigations could follow. He told reporters the administration expects to launch further Section 301 country-specific probes, potentially examining rice and seafood markets. He added that he does not expect new Section 232 national security investigations in the coming weeks.
The timing has diplomatic significance. Treasury Secretary Scott Bessent will meet Chinese Vice Premier He Lifeng in Paris on Sunday and Monday for trade talks, setting the stage for President Trump’s state visit to Beijing from March 31 to April 2—the first U.S. presidential trip to China since Trump’s 2017 visit.
Section 301 authority allows the trade representative to impose tariffs, restrict imports, or take other trade measures in response to unfair foreign practices. The 1974 law does not specify limits on duty rates or duration, giving the administration more flexibility than the balance-of-payments statute underlying the current global tariff.
The investigations launch as the administration races to rebuild its tariff framework after the Supreme Court’s February decision. Whether this legal approach proves more durable than the prior one will likely be decided by the courts—and by whether Congress extends the Section 122 tariffs before they expire in July.