April 29 (UPI) -- The United States has sanctioned 35 entities and individuals accused of overseeing a shadow-banking network that moved tens of billions of dollars for Iran, as the Trump administration flexes Washington's financial might amid a stalemate in peace negotiations with Tehran. The sanctions announced Tuesday come as U.S.-Iran peace negotiations came to a halt last week after Tehran said it would not participate in talks until the United States lifted its blockade of sea-based trade