As expected, President Trump signed off on steel and aluminum tariffs Thursday at the White House, CNBC reports. Trump says a 25% tax will apply to steel imports, and 10% will be added to aluminum brought into the US, the AP reports. Trump says the excess of imported steel and aluminum is a "travesty" and hurts American workers and industry and that the US industry has been "ravaged by aggressive foreign trade practices. ... It's really an assault on our country." The tariffs will take effect in 15 days, with Canada and Mexico indefinitely exempted. Trump, who announced the tariffs while surrounded by steelworkers, says he is fulfilling a key campaign promise. American steel and aluminum workers have been betrayed, he said, but "that betrayal is now over." (More President Trump stories.)