Newsweek has contacted the EU for a full list of U.S. goods it plans to hit with new trade taxes. Trump hit EU imports with a 20 percent tariff on April 2, claiming the EU already had tariff measures against the U.S. that equated to 39 percent. This came after he imposed 25 percent tariffs on auto imports, as well as aluminum and steel.

The tariffs were slated to take effect starting on April 15, and to hit back at President Trump’s steel and aluminum levies.

But the European Commission President warned: "If negotiations are not satisfactory, our countermeasures will kick in."