Wall Street had its worst week since early April after President Trump said he would impose steep tariffs on E.U. goods and targeted Apple with a tax on foreign-made iPhones.

President Trump lashed out at Apple CEO Tim Cook as he wielded more tariff threats against the European Union pressuring U.S. stocks which are on pace for weekly losses. The 10-year Treasury yield hovered near 4.

U.S. stock index futures turned lower on Friday as shares of Apple dropped after U.S. President Donald Trump said the company would have to pay a 25% tariff if phones sold in the country are not made within its borders.