On Thursday, a federal appeals court will hear oral arguments in a case that could determine the fate of the Trump tariffs.

Trump has justified his most far-reaching assertions of tariff power by citing the 1977 International Emergency Economic Powers Act, which allows tariffs on all imports during an "unusual and extraordinary threat ... to the national security, foreign policy or economy of the United States."

As President Donald Trump prepares to announce new tariff increases, the costs of his policies are starting to come into focus for a domestic manufacturing sector that depends on global supply

The White House cited national security concerns for its tariff on copper, and Trump asked for restrictions on the export of copper scrap.