U.S. stock markets declined as Trump escalated trade tensions, with the Dow Jones falling 0.56%, S&P 500 down 0.69%, and Nasdaq dropping 0.97%. Trump threatened Apple with a 25% tariff unless iPhones are manufactured in the U.S., causing Apple's stock to fall 2.6%. He also warned of potential 50% tariffs on EU goods starting June 1, citing stalled trade negotiations.