.Biden preparing to obstruct Nippon Steel investment of U.S. Steel The Washington PostU.S. Steel mentions it might leave behind Pittsburgh if Nippon bargain fails as Biden plans to block out requisition Pittsburgh Post-GazetteBiden Expected to Block U.S. Steel Requisition The New York TimesExclusive|U.S. Steel Warns of Vegetation Closings if Sale Collapses The Exchange JournalBiden prepped to block US Steel purchase through Nippon Steel CNN.