Britain on Wednesday advised British-Iranian dual nationals against all but essential travel to Iran, tightening up its existing travel advice and warning it has only limited powers to support them if detained. "The Foreign Secretary (Jeremy Hunt) has taken the decision to advise against all but essential travel by UK-Iranian dual nationals to Iran," a foreign office spokeswoman said in an emailed statement, according to Reuters. "British citizens who also hold Iranian nationality face risks if they travel to Iran, as we have seen all too sadly in a number of cases," it said. "The Iranian government does not recognize dual nationality so if a dual national is detained our ability to provide support is extremely limited," the statement added.