The Obama administration unveiled a host of new sanctions Friday against more than 30 companies and individuals doing business in or with Iran, seeking to thwart that nation’s nuclear ambitions, its support for organizations the United States deems as terrorist groups and mute its support for the embattled regime of Syrian leader Bashar Assad. The sanctions come at a period where the United States needs Iran’s help in trying to defeat the Islamic State (ISIS). Friday’s additions to the list include more banks, providers of equipment to Iran’s state oil company, banks that help to funnel U.S. currency to Iran’s central bank and transport-related businesses that have helped the Syrian and Iranian governments.