.Biden prepping to obstruct Nippon Steel acquisition of united state Steel The Washington PostU.S. Steel claims it might leave behind Pittsburgh if Nippon offer fails as Biden considers to obstruct takeover Pittsburgh Post-GazetteBiden Expected to Block U.S. Steel Requisition The Nyc TimesExclusive|U.S. Steel Portend Vegetation Closings if Purchase Collapses The Wall Street JournalBiden prepped to block US Steel purchase by Nippon Steel CNN.