.Biden readying to obstruct Nippon Steel acquisition of U.S. Steel The Washington PostU.S. Steel mentions it might leave Pittsburgh if Nippon package falls through as Biden plans 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 Collapses The Exchange JournalBiden prepped to block out United States Steel investment by Nippon Steel CNN.