Global markets plunged after President Donald Trump reignited fears of a U.S. trade war with the European Union, America's largest trading partner, after his threat of new tariffs on seven E.U. countries unless they supported his push for American control of Greenland.

The S&P 500 ended lower by around 2.1%, erasing the index's gains for the year so far. The Nasdaq Composite plunged more than 2.4%, and the Dow Jones Industrial Average dropped around 870 points.