.Biden preparing to block Nippon Steel purchase of united state Steel The Washington PostU.S. Steel claims it might leave behind Pittsburgh if Nippon deal falls through as Biden plans to obstruct takeover Pittsburgh Post-GazetteBiden Expected to Block United State Steel Takeover The New York City TimesExclusive|USA Steel Portend Plant Closings if Sale Breaks Down The Wall Street JournalBiden prepped to obstruct United States Steel acquisition by Nippon Steel CNN.