In April, administration officials vowed to sign trade deals with as many as 90 countries in 90 days. The ambitious target came after Mr. Trump announced, and then rolled back a portion of, steep tariffs that in some cases meant import taxes cost more than the wholesale price of a good itself.

The U.S. Court of International Trade on Wednesday struck down tariffs imposed on virtually every country by President Donald Trump, ruling that he exceeded the authority granted to him under the 1977 International Emergency Economic Powers Act.