.Biden preparing to block Nippon Steel acquisition of U.S. Steel The Washington PostU.S. Steel mentions it might leave behind Pittsburgh if Nippon package fails as Biden intends to block takeover Pittsburgh Post-GazetteBiden Expected to Block USA Steel Takeover The New York TimesExclusive|United State Steel Portend Plant Closings if Purchase Falls Down The Exchange JournalBiden readied to shut out US Steel investment by Nippon Steel CNN.