President Donald Trump announced Friday that he is doubling the tariff on steel to 50 percent, a sharp escalation that could drive up costs for housing, automobiles, and other steel-based goods as he announced what he called "a blockbuster agreement" to let U.S. Steel merge with Japan's Nippon Steel.Speaking at U.S. Steel's Mon Valley Works–Irvin Plant in West Mifflin, Pennsylvania, Trump highlighted Japan's Nippon Steel while defending his administration's trade policies. Since he took office, the price of steel products has risen by approximately 16 percent, according to the government's producer price index.Trump told workers, "It's headquartered in the great city of Pittsburgh, Pennsylvania, where it belongs."The president announced Nippon Steel's "record-setting" $14 billion commitment to future of the company."This is the single-largest investment of any kind in the history of the Commonwealth of Pennsylvania, and the largest-ever in the U.S. steel industry."President Trump said $2.2 billion of the investment is specifically for the Mon Valley U.S. Steel plant. As part of the deal, U.S. Steel facilities will also be built in Indiana, Alabama, Arkansas and Minnesota.Before stepping on stage, the president spoke briefly with three workers who presented him with a golden hard hat. Trump smiled, held it up, and pointed it out to reporters nearby—but didn't wear it.He also chatted with the workers as they walked past massive rolls of steel. Trump looked around the facility, closely inspecting the coils and other nearby steel products, including household appliances on display.This is developing news and will be updated as more information is available.