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.

If he moves forward with the tariffs, it could have ramifications for nearly every aspect of the global economy.

The United States will start charging 30% tariffs on August 1 on products coming into the country from the European Union and Mexico, President Donald Trump confirmed in separate letters Saturday.