.Biden prepping to block Nippon Steel purchase of united state Steel The Washington PostU.S. Steel mentions it might leave Pittsburgh if Nippon package falls through as Biden intends to shut out requisition Pittsburgh Post-GazetteBiden Expected to Block United State Steel Takeover The New York City TimesExclusive|U.S. Steel Portend Plant Closings if Sale Collapses The Stock market JournalBiden readied to shut out US Steel acquisition by Nippon Steel CNN.