China has suspended exports of a wide range of critical minerals and magnets, threatening to choke off supplies of components central to automakers, aerospace manufacturers, semiconductor companies and military contractors around the world.

Shipments of the magnets, essential for assembling everything from cars and drones to robots and missiles, have been halted at many Chinese ports while the Chinese government drafts a new regulatory system. Once in place, the new system could permanently prevent supplies from reaching certain companies, including American military contractors.

President Donald Trump knows his hike in tariffs for China's goods to 145 percent will up the ante in a trade war, but Beijing also holds a strong hand with its control of the materials critical for the United States defense industry.

China first responded on April 3 to Trump's initial salvo of 54 percent levies on its exports by placing export restrictions on rare earth elements, which are key for the fighter aircraft that will form the backbone of the U.S. Air Force's next-generation fleet.

China will pause exports of critical minerals to the United States in the country’s latest move to counteract President Donald Trump’s tariffs. Trump has set a tariff on China at a hefty 145%, which it has responded to with a 125% reciprocal tariff.

The U.S. granted tariff exemptions on laptops, smartphones, and other items. China called on the U.S. to “completely cancel” its tariffs, saying that the exemptions were a “small step” toward doing so.