.Biden prepping to obstruct Nippon Steel purchase of U.S. Steel The Washington PostU.S. Steel claims it could leave Pittsburgh if Nippon offer falls through as Biden prepares to block takeover Pittsburgh Post-GazetteBiden Expected to Block USA Steel Requisition The The Big Apple TimesExclusive|United State Steel Warns of Vegetation Closings if Purchase Breaks Down The Exchange JournalBiden readied to block US Steel purchase by Nippon Steel CNN.