"We should continue our policy of sanctions, strengthen them more and I think that's far better than military action which makes no sense," said Bill Richardson, a former New Mexico governor who served as energy secretary under Bill Clinton. "You see the moderate forces in the Iranian government that recognise that they have to negotiate being strengthened, and that's what we want."
The US president Barack Obama recently signed a fourth round of sanctions on the Iranian energy and finance sectors since 2010. The European Union and other nations have matched with their own measures.
Iran is one reason that American alliances with Arabian Gulf states will remain strong despite a diminished energy trade, said Mr Richardson. The majority of GCC oil goes to East Asia, while some in the US entertain hopes of energy independence after a shale oil and gas boom.
"We have a lot of interests here - economic, political interests, cultural interests," he said. "I think the Gulf states offer right now energy stability and they offer political stability and we have a strong defence relationship, and I don't think that will be altered."