Global markets tumbled and governments scrambled to respond on Thursday, just hours after President Donald Trump imposed sweeping new tariffs on dozens of countries — a move economists warn could ignite a global trade war.

Speaking from the White House Rose Garden on Wednesday afternoon, Trump said he was placing elevated tariff rates on dozens of countries in response to their respective trade barriers with the United States, as well as a baseline 10% tax on all imports. The announcement came on the heels of a March 26 directive imposing 25% tariffs on cars and light trucks imported into the United States, effective April 2. 

The move sent shockwaves across the global economy, with many political leaders expressing concern and saying they wanted to negotiate with the United States to garner some concessions. On Thursday, stock markets from London and Paris to Beijing and Tokyo fell. Oil slumped by more than 6% as investors worried that Trump had stoked a global trade war that would dampen economic growth and energy demand. However, oil and gas were exempt from the new tariffs.

Beijing, Washington’s principal political rival, was hit hardest — facing another 34% tariff from the US. China was already subject to a 20% levy, so in total it now has to pay 54% on all exports to the US. The European Union, Japan and South Korea were also hit — at 20%, 24% and 25%, respectively. Gulf nations and Turkey were spared the worst, facing only the baseline 10%, as they maintain a trade surplus with the US rather than a deficit. Bahrain, Oman, Israel, Jordan and Morocco have had existing free trade agreements with Washington for years.