.Biden prepping to block Nippon Steel investment of U.S. Steel The Washington PostU.S. Steel says it might leave Pittsburgh if Nippon offer fails as Biden plans to obstruct takeover Pittsburgh Post-GazetteBiden Expected to Block USA Steel Requisition The New York City TimesExclusive|United State Steel Portend Vegetation Closings if Sale Falls Down The Exchange JournalBiden prepared to obstruct US Steel purchase through Nippon Steel CNN.