President Donald Trump's economic agenda was dealt a crushing blow, with the U.S. Court of Appeals for the Federal Circuit striking down his authority to enact tariffs under the International Emergency Economic Powers Act.

The ruling potentially guts a core policy of the Trump administration, which has imposed sweeping tariffs on goods from virtually the entire world, using them both to try to spur U.S. domestic production and to create leverage to bargain for better trade deals with foreign countries.

The decision, however, is on hold from taking effect until Oct. 14, which will give Trump extensive time to appeal to the Supreme Court.

In the decision, the court upheld a lower decision from the U.S. Court of International Trade, finding that Trump's use of IEEPA to enact tariffs was well outside the authority granted by that law.

"The Challenged Executive Orders in this case exceed the authority provided by [the government's] interpretation of IEEPA. Both the Trafficking Tariffs and the Reciprocal Tariffs are unbounded in scope, amount, and duration," stated the court. "These tariffs apply to nearly all articles imported into the United States (and, in the case of the Reciprocal Tariffs, apply to almost all countries), impose high rates which are ever-changing and exceed those set out in the HTSUS, and are not limited in duration."

Thus, the court wrote, "the Trafficking and Reciprocal Tariffs assert an expansive authority that is ... beyond the authority delegated to the President by IEEPA."