President Donald Trump said Friday that he's doubling the tariff rate on steel to 50%, a dramatic increase that could further push up prices for a metal used to make housing, autos and other goods. Trump spoke at U.S. Steel’s Mon Valley Works–Irvin Plant in West Mifflin, Pennsylvania, near Pittsburgh to discuss investments by Japan’s Nippon Steel. The price of steel products has increased roughly 16% since Trump became president, according to the government’s producer price index. Trump said U.S. Steel will stay an American company under a deal for Japan-based Nippon to invest in the iconic American steelmaker. Few details about the deal have been made public. Trump said doubling the tariffs on imported steel “will even further secure the steel industry in the U.S.” But such a dramatic increase could push prices even higher. Employees, Trump supporters, local officials and others filled one of the massive warehouses on the grounds of the Irvin finishing plant to hear Trump. Giant American flags hung from the ceiling and a sign read, “The Golden Age." Steelworkers in orange hard hats and work clothes milled about, and part of the warehouse’s cement floor was packed with huge rolled coils of shiny steel sheet produced at the plant and used for appliances, doors and other applications. Trump, who has been eager to strike deals and announce new investments in the U.S. since retaking the White House, is also trying to satisfy voters, including blue-collar workers, who elected him as he called to protect U.S. manufacturing.