.Biden preparing to obstruct Nippon Steel purchase of united state Steel The Washington PostU.S. Steel says it could possibly leave Pittsburgh if Nippon bargain falls through as Biden organizes to obstruct takeover Pittsburgh Post-GazetteBiden Expected to Block U.S. Steel Takeover The New York City TimesExclusive|United State Steel Portend Vegetation Closings if Purchase Falls Down The Commercial JournalBiden prepped to obstruct United States Steel purchase by Nippon Steel CNN.