Khan, who passed away last night, retired from Pakistan Army as lieutenant general in 1971 and then embarked on a career as a diplomat.
He remained Pakistan's ambassador to France, the United States and the Soviet Union from 1972 to 1982.
Khan served as foreign minister from 1982 to 1991. He also served as caretaker foreign minister from 1996 to 1997.
President Mamnoon Hussain and Prime Minister Nawaz Sharif have expressed grief over his demise.