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,

Prices for the metal hit a record high after the president suggested a higher rate than many analysts were expecting.

While the cost of copper is going up for American businesses and consumers, the rest of the world is scratching its head while it enjoys a considerable discount on the price of copper.