Ivan Smith joined the United Nations in 1947 and went to New York as Senior Director of External Affairs to establish the organisation's first international radio programmes for the United Nations Information Services, then at Lake Success, New York (1947-1949).
He was also in charge of press liaison at the Four Powers' summit conference and foreign ministers' meeting in Geneva in 1955 and worked closely with James Hagerty President Dwight Eisenhower's press secretary.