The president has ratcheted up the rate on foreign metals to 50 percent, double the previous rate, saying the levies weren’t high enough to help the U.S. industry.

Trump made his latest tariff announcement at a US Steel Corp facility in West Mifflin, Pennsylvania, on Friday. "At 25 percent, [US trading partners] can sort of get over that fence," he said. "At 50 percent, nobody's getting over that fence."

US tariffs on steel and aluminum doubled to 50% as of 12:01 am ET on Wednesday, a move cheered by the beleaguered US steel industry but decried by heavy users of the metals, from car makers to can manufacturers.