Trump has rolled back many of his steepest tariffs over recent months, including a sky-high levy on China, the top source of U.S. imports. In recent days, however, Trump announced plans to slap tariffs as high as 50% on dozens of countries, including 25% tariffs on top U.S. trade partners such as Japan and South Korea.

The US president’s hardened stance aims to test the EU’s pain threshold after weeks of talks on a framework agreement that would have maintained a baseline tariff of 10 per cent on most goods. Trump has also been unmoved by the latest EU offer to reduce car tariffs,