The US has refused to grant a visa to Iran's new ambassador to the United Nations, due to his alleged involvement in the group behind the 1979 takeover of the US Embassy in Tehran. This would effectively prevent him from assuming his duties at the New York-based United Nations.

CNN reports that Hamid Aboutalebi--a veteran diplomat with posts in Australia, Belgium, and Italy--was a member of the Muslim Students Following the Imam's Line, which held fifty-two Americans hostage for 444 days at the Embassy.

He reportedly denies involvement and says he was only later asked to translate for the group. He is also alleged to be involved in the murder of an Iranian government defector, Mohamed Hossein Naghdi, who was shot dead in Rome.

CNN reports that Iran is standing by his nomination despite the visa refusal.

The BBC states: "It is believed the US has never before denied a visa for a UN ambassador and correspondents say there is concern among diplomats about the precedent that could be set."