WASHINGTON - President Donald Trump opened yet another front on Tuesday in his assault on global trade norms, ordering a probe into potential new tariffs on copper imports to rebuild US production of a metal critical to electric vehicles, military hardware, the power grid and many consumer goods.

Trump, looking to thwart what his advisers see as a move by China to dominate the global copper market, signed an order at the White House directing Commerce Secretary Howard Lutnick to start a national security probe under Section 232 of the Trade Expansion Act of 1962. That is the same law Trump used in his first term to impose 25% global tariffs on steel and aluminum.

A White House official, briefing reporters on condition of anonymity, said any potential tariff rate would be determined by the investigation, adding that Trump preferred tariffs over quotas.

The move is the latest by Trump to upend decades of business support for free trade that he railed against as both candidate and president for hollowing out the US industrial base, an upheaval now aimed at long-time US allies like Canada and Mexico as well geopolitical adversaries like China.

He has issued a cascade of tariff orders since taking up residency in the White House for a second term last month. While only a new 10% levy on all imports from China is in place, 25%duties on goods from Canada and Mexico are set to take effect next week and others aimed at steel, aluminum and motor vehicles will follow shortly afterward or are in fast-track development.

Trump's blitz has begun to take a toll on consumer confidence, which had initially surged following his election victory in November over former President Joe Biden as Trump promised to bring down living costs. Earlier on Tuesday the Conference Board reported the largest drop in consumer confidence in three-and-a-half years, with households expecting a resurgence in inflation.

Ahead of the copper announcement, stocks fell on Wall Street for a fourth straight day, a drop pinned on growing uncertainty about Trump policies on trade in particular.

But there were pockets of upside among perceived winners: Shares of the world's largest copper producer, Phoenix-based Freeport-McMoran shot up 5% in after-hours trading. The company, which produced 1.26-billions of copper in the US last year, did not immediately respond to a request for comment.

London-based Antofagasta declined to comment on Trump's action. The company is trying to develop the $1.7-billion Twin Metals copper and nickel mine in Minnesota, but saw its mineral rights blocked under former president Biden's administration over water pollution concerns.

Trump has vowed to ease regulations on businesses to boost US economic growth.

TARGETING CHINA

White House trade adviser Peter Navarro said the investigation would be completed quickly, "in Trump time."

Navarro said China was using state subsidies and excess capacity to undermine competition and gain control over global copper production, in much the same way it now dominates steel and aluminum production.

That said, the countries set to be most affected by any new US copper tariffs would be Chile, Canada and Mexico, which were the top suppliers of refined copper, copper alloys and copper articles in 2024, according to US Census Bureau data.

"Like our steel and aluminum industries, our great American copper industry has been decimated by global actors attacking our domestic production," Lutnick said during the White House signing session, vowing to end unfair trade practices that have put Americans out of work.

"American industries depend on copper, and it should be made in America, no exemptions, no exceptions," he said. "It's time for copper to come home."

A White House fact sheet said the investigation would assess the national security risks from growing US dependence on imported copper "in all its forms," citing data showing the U.S. depended on imports for 45% of its copper consumption last year, up sharply from the early 1990s.

The White House official said the investigation, which also includes the US Trade Representative's office, would look at imports of raw mined copper, copper concentrates, copper alloy, scrap copper and derivative products made from the metal. The official declined to identify any specific derivatives, saying that would prejudge the investigation.

The official said the Department of Energy recognized copper as a critical material in the medium term due to increased demand for solar energy technologies and global electrification, noting that it was the second most widely used material in US weapons platforms.

MORE CAPACITY NEEDED

The official said based on current demand for electric vehicles and power-hungry artificial intelligence applications, there will be a US copper shortage in the future, and the United States cannot develop adequate copper smelting and refining capacity unless there is a reasonable certainty of long-lasting trade protection for the sector.

During Tuesday's signing, Lutnick also said the Trump administration would hold countries accountable for imposing digital services taxes on US technology firms including Google, Apple and Amazon. Trump on Friday ordered USTR to revive tariff investigations into these taxes.

"Both friend and foe have been treating American tech companies, partially, as if our companies are their piggy bank," Lutnick said. "This will now end. It is my objective to level the playing field and end these attacks."