AP Photo
FILE - In this file photo taken Wednesday, Dec. 5, 2007, a Chinese worker performs welding work on steel rods using a steel drill at a construction site in Beijing. China says it "firmly opposes" U.S. President Donald Trump's tariff increase for imported steel and aluminum but gave no indication whether Beijing might impose its own measures in response. A government statement issued Friday, March 9, 2018, accused Trump of damaging the global trading system. (AP Photo/Ng Han Guan, File)