In rare move against another country's top diplomat, Washington freezes Mohammad Javad Zarif's assets, appearing to close door on negotiations

As Iranian rial hits record low, Tehran decides on move to simplify transactions; nation's coin will be known as 'toman'

FM Zarif claims increased tensions are 'due to America's economic terrorism and Europe's inability to fulfill its commitments'

Israeli intelligence sources said to estimate that Tehran has increased its involvement in Strip in effort to turn terror group into its operational arm against Israel

Jason Greenblatt says Tehran's aggression has brought Arab nations and Israel together to an unprecedented degree, urges global community to back Trump plan

Sale to go ahead after lawmakers unable to override veto on bill blocking $8.1 billion in weapons sales to Riyadh, Abu Dhabi despite bipartisan concerns

London dispatches warship to Gulf to escort UK-flagged tankers across world's busiest oil shipping lane amid escalating tensions

Government spokesperson says Washington's top envoy can come and meet US-born Marzieh Hashemi, a convert to Islam and presenter on Iranian TV

Top Tehran security official holds talks with Omani minister in charge of foreign affairs amid escalating tanker crisis

Meeting between foreign ministers seen as possible effort to diffuse standoff between Tehran and London, after former seized British-flagged tanker in Strait of Hormuz