People walk past the Apple Fifth Avenue store in New York City, US, May 23, 2025. (Photo: REUTERS)

The twin threats, delivered via social media, roiled global markets after weeks of de-escalation had provided some reprieve in the tariff battle.

Major US stock indexes and European shares fell and the dollar weakened, while the price of gold, a safe-haven for investors, rose. US Treasury yields fell on fears about tariffs' effect on economic growth.

Trump's broadside against the EU was prompted by the White House's belief that negotiations with the bloc are not progressing fast enough.

And the president's threat on Apple is his latest attempt to pressure a specific company to move production to the United States, following automakers, pharmaceutical companies and chipmakers. The United States, however, does not mass-produce smartphones - even as US consumers buy more than 60 million phones annually - and moving production would likely increase the cost of iPhones by hundreds of dollars.

Later on Friday, Trump told reporters inside the Oval Office that his proposed tariff on Apple would also apply to "Samsung and anybody that makes that product," apparently referring to smartphones. He said he expected the new phone levy to be in place by the end of June.