.Biden prepping to block Nippon Steel investment of U.S. Steel The Washington PostU.S. Steel says it could leave Pittsburgh if Nippon offer flops as Biden prepares to block out takeover Pittsburgh Post-GazetteBiden Expected to Block United State Steel Takeover The New York City TimesExclusive|U.S. Steel Portend Plant Closings if Purchase Falls Down The Wall Street JournalBiden prepared to shut out United States Steel acquisition through Nippon Steel CNN.