.Biden prepping to block Nippon Steel acquisition of U.S. Steel The Washington PostU.S. Steel claims it could possibly leave behind Pittsburgh if Nippon deal fails as Biden considers to block takeover Pittsburgh Post-GazetteBiden Expected to Block USA Steel Requisition The New York City TimesExclusive|U.S. Steel Warns of Plant Closings if Sale Falls Down The Wall Street JournalBiden readied to block United States Steel investment through Nippon Steel CNN.