U.S. President Donald Trump has ordered a probe into possible tariffs on copper imports to rebuild U.S. production of a metal critical to electric vehicles, military hardware, semiconductors, and a wide range of consumer goods. The investigation will examine imports of raw mined copper, copper concentrates, copper alloy, scrap copper, and derivative products made from the metal. The United States produces domestically just over half the refined copper it consumes each year, with more than two-thirds of that mined in Arizona. The remaining refined copper, just shy of 1 million metric tons annually, is imported. Most of the U.S.’s refined copper imports come from the Americas, with Chile, Canada, and Peru accounting for more than 90% of imports last year, according to the United States Geological Survey (USGS). China dominates global copper refining, but most of the ore that feeds into its smelters is mined elsewhere, in particular in Latin America. Chile and Peru together mined roughly a third of global copper last year, according to the USGS. However, China is expanding its control over world copper mining through its major investments in mines in the Democratic Republic of the Congo (DRC). The DRC is now the world’s second-largest copper miner after overtaking Peru, due in large part to massive Chinese investment in the African country’s mining sector. The Chinese copper smelting sector dwarfs all others. The country had dozens of copper smelters operating last year. Meanwhile, the United States has only two primary copper smelters, according to the USGS.