.Biden preparing to block out Nippon Steel purchase of united state Steel The Washington PostU.S. Steel states it could leave Pittsburgh if Nippon package falls through as Biden organizes to block requisition Pittsburgh Post-GazetteBiden Expected to Block U.S. Steel Requisition The New York TimesExclusive|United State Steel Portend Plant Closings if Sale Breaks Down The Exchange JournalBiden prepared to shut out US Steel purchase by Nippon Steel CNN.