.Biden preparing to block out Nippon Steel purchase of united state Steel The Washington PostU.S. Steel claims it could possibly leave behind Pittsburgh if Nippon offer falls through as Biden plans to block takeover Pittsburgh Post-GazetteBiden Expected to Block United State Steel Requisition The Nyc TimesExclusive|USA Steel Portend Plant Closings if Sale Falls Down The Exchange JournalBiden readied to block United States Steel purchase through Nippon Steel CNN.