President Donald Trump on Saturday threatened duties of 30% on products from Mexico and the European Union, two of America’s biggest trading partners, in an ongoing tariff campaign that’s upended global trade since he retook office in January.

Leaders from both economies had been trying to negotiate more favorable terms, only to have those efforts blown up by form letters.

U.S. President Donald Trump announced on Saturday a 30% tariff rate for goods imported from the European Union and Mexico, starting on August 1. The EU had initially hoped to reach a comprehensive trade agreement with the U.