.Biden readying to block Nippon Steel investment of united state Steel The Washington PostU.S. Steel states it can leave Pittsburgh if Nippon deal falls through as Biden organizes to shut out requisition Pittsburgh Post-GazetteBiden Expected to Block United State Steel Requisition The Nyc TimesExclusive|U.S. Steel Portend Plant Closings if Purchase Falls Down The Commercial JournalBiden prepared to obstruct United States Steel purchase through Nippon Steel CNN.