States sue to block Trump's 10% global tariff on US imports

A coalition of nearly a dozen states has sued the Trump administration to block the 10% global tariff imposed after a recent US Supreme Court decision on tariffs.

President Donald Trump signed a proclamation on Feb. 20 implementing a 10% global tariff under Section 122 of the Trade Act of 1974, the same day the high court overturned his country-specific duties. The law authorizes a president to impose temporary tariffs of up to 15% for 150 days.

The coalition, led by New York Attorney General Letitia James, filed a lawsuit with the US Court of International Trade on March 5. The states are seeking an order blocking Section 122 tariffs from taking effect and requiring the federal government to refund tariffs costs paid by the states.

The lawsuit argues that the tariffs do not meet the requirements of Section 122 and violate the Constitution's separation of powers. The states contend that only Congress has the authority to tax and impose tariffs.

The Supreme Court cited a similar argument in its earlier decision, finding that the International Emergency Economic Powers Act of 1977, which Trump invoked to impose country-specific duties, does not authorize a president to impose tariffs through executive action.

The coalition also argues that Trump's order fails to meet other Section 122 requirements, including that tariffs be applied consistently without product exceptions and that they address a qualifying "balance of payments" deficit required by the law.

In the filing, the states said that Trump's changes to tariff policy have created significant costs for the states as agencies attempt to interpret policy through social media posts, executive orders, proclamation and other sources.

The Trump administration will "vigorously defend the president's action in court," White House spokesperson Kush Desai said in a statement to Platts, part of S&P Global Energy.

"The President is using his authority granted by Congress to address fundamental international payments problems and to deal with our country’s large and serious balance-of-payments deficits," Desai said.

James was joined by attorneys general from 21 other states, as well as Pennsylvania Gov. Josh Shapiro and Kentucky Gov. Andy Beshear. James led a similar lawsuit in April 2025 with 11 other attorneys general to halt the IEEPA tariffs.

No president has previously imposed tariffs under Section 122. Trade attorneys have raised legal questions about the statute's use, but said courts may be reluctant to block a tariff scheduled to last only five months. However, if Trump attempts to extend the 150-day window or issue a new proclamation restarting the clock, the administration could face additional litigation.

The Section 122 tariff exempts goods that comply with the United States-Mexico-Canada Agreement, and it does not stack on top of Section 232 sectoral tariffs, which include 50% duties on steel, aluminum and copper imports.

While most metals are exempt from the Section 122 tariffs, some materials, including pig iron, would be subject to the new rate. However, the 10% duty is lower for some countries than the per-country tariffs previously imposed under the IEEPA duties.

Other materials, such as aluminum scrap, are mostly exempt from Section 122 because they fall under the exemptions for USMCA-compliant goods from Canada and Mexico.