.Biden preparing to block Nippon Steel purchase of USA Steel The Washington PostU.S. Steel mentions it can leave behind Pittsburgh if Nippon deal fails as Biden considers to block out requisition Pittsburgh Post-GazetteBiden Expected to Block United State Steel Takeover The New York City TimesExclusive|USA Steel Portend Plant Closings if Sale Collapses The Exchange JournalBiden prepped to block United States Steel acquisition through Nippon Steel CNN.