Ardeshir Zahedi GCVO ( Persian : اردشیر زاهدی ; 16 October 1928 – 18 November 2021) was a prominent Iranian politician and diplomat who served as the country's foreign minister from 1966 to 1971, and its ambassador to the United States and the United Kingdom during the 1960s and 1970s. He was the last official Iranian ambassador to the US. He resigned his position following the Iranian revolution in 1979 and overthrow of the Pahlavi dynasty .