MaterialsUpgrade, costing double initial plan, would support over 6,000 jobs, report saysU.S. Steel's Edgar Thomson Plant will receive a state-of-the-art hot strip mill. (Photo by Hiroki Endo)AZUSA KAWAKAMIJune 9, 2026 04:32 JSTNEW YORK -- Japan's Nippon Steel will spend $2 billion to $2.5 billion to upgrade U.S. Steel's Mon Valley Works in the state of Pennsylvania, more than double the amount initially pledged by the Japanese steelmaker, the American subsidiary revealed in a report Monday.