.Biden preparing to block out Nippon Steel acquisition of united state Steel The Washington PostU.S. Steel states it could leave behind Pittsburgh if Nippon package flops as Biden plans to block out requisition Pittsburgh Post-GazetteBiden Expected to Block United State Steel Requisition The New York TimesExclusive|USA Steel Portend Vegetation Closings if Sale Falls Down The Commercial JournalBiden readied to block out United States Steel investment by Nippon Steel CNN.