Most European markets took a hit as trading resumed in the wake of President Trump's latest tariff threats, and as the EU keeps hoping for a deal.

CNBC's Megan Casella reports on President Trump's tariff announcement on Mexico and the European Union, set to take effect August 1.

U.S. stock futures are lower after President Donald Trump further escalated trade tensions. Over the weekend, Trump announced a 30% tariff on goods from the European Union and Mexico, starting Aug. 1. Mexico and EU leaders said they would continue to negotiate this month before that date.