U.S. President Donald Trump's threat of a 50% tariff on copper imports is raising alarm in the U.S. auto sector, as it could make it even harder for carmakers and suppliers to absorb border taxes and rising costs,

President Donald Trump announced on Wednesday night that the United States will impose a 50 percent tariff on copper, effective August 1. Trump wrote on Truth Social that he came to the decision after a "robust NATIONAL SECURITY ASSESSMENT."

President Donald Trump mentioned Tuesday — almost in passing — that he planned to impose a 50% tariff on copper imports. It still hit like a bombshell, with potential to shake up U.S. efforts to expand,