Apple’s efforts to diversify its production away from China have been undermined by President Trump’s renewed threat to impose a 25% tariff on iPhones not made in the US.

Stock markets declined after the president’s early-morning threats of 25 percent import taxes on iPhones and 50 percent on goods from Europe.

President Donald Trump on Friday threatened a 50% tax on all imports from the European Union as well a 25% tariff on Apple products unless iPhones are made in America. The threats, delivered over social media,