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.

Letters went to 23 other American trading partners this week, including Canada, Japan and Brazil, setting blanket tariff rates ranging from 20 percent

President Donald Trump posted letters to the leaders of Mexico and the European Union, saying they had not done enough to head off the new tariffs.

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

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 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.