President Trump announced in a letter posted to social media on Saturday that he would place a 30 percent tariff on goods from the European Union, upending months of careful negotiations and further roiling what is one of the world’s most important economic relationships.

President Donald Trump on Saturday announced he's levying tariffs of 30% against the European Union and Mexico. Trump announced the tariffs on two of the United States' biggest trade partners in letters posted to his social media account.