.Biden preparing to block Nippon Steel acquisition of U.S. Steel The Washington PostU.S. Steel claims it could possibly leave behind Pittsburgh if Nippon deal flops as Biden prepares to block out requisition Pittsburgh Post-GazetteBiden Expected to Block United State Steel Requisition The The Big Apple TimesExclusive|U.S. Steel Portend Plant Closings if Purchase Collapses The Wall Street JournalBiden readied to block US Steel acquisition through Nippon Steel CNN.