China's growing copper reserves have caught the eye of President Donald Trump, who on Tuesday ordered an investigation into what administration officials say is Beijing's move to "gain control of the world's copper markets."

Trump, in the Oval Office, asked his newly minted secretary of commerce, Howard Lutnick, to explain. Lutnick read from what he said was a social media post he planned to release, saying: "Tariffs will help rebuild back our American copper industry and strengthen our national defense. American industries depend on copper, and they should be made in America. No exemptions, no exceptions. America first creates American jobs and protects our national security. It's time for copper to come home."

Earlier in the day, Trump's senior counselor for trade and manufacturing explained the administration's concerns.

"China has long used industrial overcapacity and dumping as an economic weapon to dominate global markets, systematically undercutting competitors and driving rival industries out of business by massively subsidizing key industries, flooding international markets with below-cost goods and then consolidating control once competitors collapse," Peter Navarro said in a call with reporters ahead of the signing. "China has successfully expanded its economic influence in sectors ranging from steel and aluminum to solar panels and electric vehicles."

Trump's order jumpstarts an investigation under the authority of the Trade Expansion Act, which focuses on whether importation of a certain item presents a threat to national security. The president can decide whether to follow the recommendations of the report, due in 270 days.

China's government released a report earlier this month where they laid out a plan to increase copper ore reserves by 5% to 10% by 2027.

Chinese government figures state that in 2024, China topped the world in the production of both refined copper and copper-processed materials.

Navarro told reporters the U.S. hopes to do more with the nation's "untapped" copper potential and cited plans to boost U.S. production by 70% and reduce external reliance on the material vital for electrical equipment.