US President Donald Trump has ordered an investigation of copper imports in what is a first step toward potential tariffs on the metal.
Administration officials said the White House wanted to find ways to boost US production of copper, a component used to make electric cars, ships and data centres that they said was vital to national security.
The move launches a process that Trump previously used to put tariffs on steel and aluminium, opening a new front in his trade war.
Trump has already raised tariffs on goods from China, while threatening a range of more sweeping trade actions, including a 25% border tax on goods from Canada and Mexico and new “reciprocal” tariffs set for each country.
The trade fights have drawn threats of retaliation, while raising alarm among consumers and businesses in the US about higher costs.
Concerns about the plans have contributed to a sharp drop in consumer confidence on recent surveys.
But administration officials said on Tuesday they believed this action was necessary to protect US copper companies from competition from China.
“China has long used industrial capacity and dumping as an economic weapon to dominate global markets, systematically undercutting competitors and driving rivals out of business,” Trump trade advisor Peter Navarro said.
“It’s time for copper to come home,” Commerce Secretary Howard Lutnick said.
Tariffs are taxes charged on goods imported from other countries, which are paid by the company that is bringing in the goods.
They are intended to support domestic production by making imports more expensive.
The US is already a major copper producer, while also importing the metal mainly from Chile, Canada and Mexico.
China’s global copper exports rose last year, as domestic demand weakened, and authorities raced to curb production.
The so-called 232 investigation by the Commerce Department will look at copper imports, as well as imports of copper “derivatives”.
The timeline of the probe was not clear. On a background briefing about the action, a White House official said the results of the investigation would inform the level of possible tariffs.