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.

"Other trading partners observing these threats will have the same mistrust of the negotiation process," experts argue.

President Trump is threatening Mexico and the European Union, two of the largest U.S. trading partners, with 30% tariffs starting in August if they don't reach a trade deal with the U.S. CBS News MoneyWatch correspondent Kelly O'Grady breaks down what this means for U.

President Donald Trump on Wednesday announced that he will send tariff letters to over 150 countries as the August 1 deadline to enforce the levies approaches. President Trump made the announcement while addressing reporters at the White House, according to a Bloomberg report.

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.

Latest news and live updates as Trump announces the U.S. will send Patriot missiles to Ukraine and meets with NATO's secretary general.

The decision was made to impose new, higher tariffs as he claimed the countries were taking advantage of the US. The tariffs are set to begin on August 1

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.