Brian Hook's departure comes as Washington fights a losing battle to get UN Security Council members behind new weapons limitations; he'll be replaced by Elliott Abrams

Richard Goldberg says the measures, which prevent him obtaining a visa or carrying out financial transactions with Iranian entities, are a 'badge of honor'

National Counterintelligence and Security Center says Moscow and Beijing looking for ways to affect policy, while Tehran circulating disinformation, anti-American content online

Ali Khamenei says Trump wants to use nuclear talks with Tehran 'for propaganda like negotiations with North Korea'

US secretary of state indicates Washington may seek new UN sanctions on Tehran, as signatories Russia and China continue to support embargo's scheduled end in October

'Great Prophet 14' maneuvers, held as US pushes to renew UN weapons sanctions on Tehran, include fast attack boat and drone attacks on a mock American carrier

Iran releases video showing military exercises held by paramilitary force in Strait of Hormuz, where American aircraft carrier passed through last week

Replica resembles Nimitz-class carriers US Navy routinely sails into Persian Gulf from the Strait of Hormuz; previous 2015 model was used as target in war games

Russia and China, looking to Tehran for arms contracts, oppose extension of UN Security Council moratorium on Iran that expires in October

Tehran's FM says Washington 'must be stopped before disaster' occurs after fighter jet approaches civilian flight; Iran aviation agency calls for probe by international body