In their ruling, the court's three-judge panel wrote that Trump's worldwide tariffs had exceeded his power under the International Economic Emergency Powers Act, or IEEPA, which the Trump administration cited in imposing those tariffs.

"Because of the Constitution's express allocation of the tariff power to Congress…we do not read IEEPA to delegate an unbounded tariff authority to the President," the court wrote.

The White House responded by rejecting the court's authority.

Oregon Attorney General Dan Rayfield (D), whose office is leading the states' suit, in a statement said they brought the case "because the Constitution doesn't give any president unchecked authority to upend the economy."

• The ruling "reaffirms that our laws matter, and that trade decisions can't be made on the president's whim," he added.

•. New York Attorney General Letitia James, who joined the suit, said in a statement the law makes clear that "no president has the power to single-handedly raise taxes" whenever they like.