Stocks were mixed in early trading on Monday after President Donald Trump over the weekend issued 30% tariffs on the European Union and Mexico, rekindling tensions with two of the largest U.S. trade partners and threatening to raise consumer prices.

President Trump is pushing through with his tariff agenda, unveiling a new batch of letters to country leaders outlining tariffs on goods imported from their countries beginning in August. Trump on Thursday announced a 35% tariff on Canadian goods.

The EU says the U.S. is resisting efforts to strike a trade deal and warned of countermeasures if no agreement is reached with U.S. by Aug. 1.