A federal appeals court on Friday ruled that many of President Trump’s global tariffs were issued illegally, striking a blow to his economic agenda.

The ruling from the U.S. Court of Appeals for the Federal Circuit upheld a lower court’s finding in May that the tariffs “exceed any authority granted” by a decades-old law that gives the president sweeping economic powers during a national emergency. That 1977 law, known as the International Emergency Economic Powers Act, had been invoked by the White House to justify many of the import taxes.

Mr. Trump used the law in April to impose tariffs on dozens of countries, including some of America’s closest allies. He was able to issue the tariffs by declaring a national emergency over the “large and persistent” trade deficit that the United States runs with the rest of the world. The president said that trade deficit — the gap between what America exports and imports — reflected unfair trade relationships that have hollowed out U.S. manufacturing.

He also used the law in February to hit Mexico, Canada and China with levies because they had “failed” to do more to stop the flow of migrants and illegal fentanyl into the United States.

Still, the court did not order the tariffs paused and instead said it would allow them to stay in place until Oct. 14, giving the government time to appeal the case to the Supreme Court.

What is IEEPA?

The International Emergency Economic Powers Act gives the president broad powers to regulate various financial transactions upon declaring a national emergency. Under the law, presidents can take a wide variety of economic actions “to deal with any unusual and extraordinary threat, which has its source in whole or substantial part outside the United States, to the national security, foreign policy or economy” of the country.