President Donald Trump on Friday threatened the European Union with a sweeping 50% tariff, posting that trade talks with the region are “going nowhere.”

In a post to his Truth Social platform, Trump wrote that he was “recommending a straight 50% Tariff on the European Union, starting on June 1, 2025.”

Trump’s post immediately sent European stock markets lower with stock indexes in Germany and France sharply dropping 2%. Shares in the U.K. dropped more than 1%. Dow futures slid more than 500 points and S&P futures dropped 1%.

The 27-nation bloc is the United States’ second-biggest trading partner behind China. The United States exported more than $350 billion of goods exported to the E.U. in recent years, and imported $550 billion worth of goods.

Maros Šefčovič, the European Commission’s trade chief, and U.S. Trade Representative Jamieson Greer were set to speak Friday. The European Commission did not immediately respond to a request for comment.