US President Donald Trump (Photo: Xinhua/VNA)

Trump ordered a Section 232 investigation into copper imports in February, using a law that gives the president authority to impose higher tariffs based on national security grounds.

This would mark the fourth across-the-board tariff Trump has imposed during his second term. Currently, most imported cars and car parts face a 25% tariff, while imported steel and aluminum both face 50% tariffs.

Copper is a crucial component in a variety of goods, including electronics, machinery and cars. Tariffs on copper could make those goods more expensive for Americans. The US imported $17 billion worth of copper last year, according to US Commerce Department data. Chile was the largest foreign supplier of the metal, shipping $6 billion worth of it to the US last year.