U.S. stock futures fell Sunday, a day after President Donald Trump threatened to impose new 30% tariffs against imports from Mexico and the European Union.

The EU – the United States' biggest trading partner – had been scheduled to impose "countermeasures" starting Monday at midnight in Brussels

President Trump plans to impose 30% tariffs on EU imports starting August 1, prompting French dairy leaders to warn of 'disastrous' impacts on their exports.

President Donald Trump released two tariff letters on Saturday, imposing duties of 30% on products from Mexico and the European Union.

President Donald Trump has posted two new letters on his social media platform announcing tariffs on the European Union and Mexico.

Financial markets, which have shown increasing insensitivity to tariff threats from the US, will face a test at the Monday open after President Donald Trump declared a 30% rate for the European Union and Mexico effective Aug.

President Trump said he plans to impose blanket levies of 15% to 20% on most trading partners that haven't yet received suggested tariff rates. That would be higher than the 10% baseline currently in effect.

Major stock indexes were slightly lower on Friday as U.S. President Donald Trump's announcement of tariffs on imports from Canada fanned worries about trade tensions, with the Canadian dollar down against the greenback.