.Biden readying to block Nippon Steel purchase of USA Steel The Washington PostU.S. Steel claims it might leave Pittsburgh if Nippon deal flops as Biden plans to block out requisition Pittsburgh Post-GazetteBiden Expected to Block U.S. Steel Takeover The New York City TimesExclusive|United State Steel Portend Vegetation Closings if Sale Breaks Down The Stock market JournalBiden readied to shut out United States Steel acquisition by Nippon Steel CNN.