.Biden readying to block out Nippon Steel acquisition of united state Steel The Washington PostU.S. Steel states it could leave Pittsburgh if Nippon offer fails as Biden plans to shut out takeover Pittsburgh Post-GazetteBiden Expected to Block U.S. Steel Takeover The Nyc TimesExclusive|United State Steel Portend Plant Closings if Sale Collapses The Commercial JournalBiden readied to block United States Steel investment by Nippon Steel CNN.