U.S. President Donald Trump on Tuesday opened yet another front in his assault on global trade norms, ordering a new probe into possible new tariffs on copper imports to rebuild U.S. production of a metal critical to electric vehicles,

Tariffs, if they are imposed, could boost U.S. production of a valuable resource but also raise costs for automakers, construction companies and others.

President Donald Trump has signed an executive action directing the Commerce Department to examine possible copper tariffs, the latest in a string of measures aimed at imposing sector-specific levies that could reshape global supply chains.