While Mexico was spared from Trump's so-called "Liberation Day" tariff rollout on April 2, the 30% rate for the E.U. is 10% higher than what the president said he would apply to America's largest trading partner in April.

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

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.

President Trump threatened a significant tariff hike on the European Union and Mexico, two of the largest U.S. trade partners, on Saturday. NBC News’ Yamiche Alcindor has more.

Mexico did not face a new tariff on April 2, the day of Trump's so-called "Liberation Day" tariff rollout. There remains a 25% tariff on non-USMCA-compliant goods from Canada and Mexico, as well as a 50% tariff on steel, aluminum and derivative products.

The global trade war is intensifying as President Trump on Saturday threatened the European Union and Mexico with tariffs.

The European Union braced on Friday for a possible letter from U.S. President Donald Trump outlining planned duties on the United States' largest trade and investment partner after a broadening of his tariff war in recent days.