In 1966, however, he aborted his political career to become the Norwegian permanent representative to the United Nations. He chaired the Sixth Committee (Legal Committee) at the 22nd United Nations General Assembly in 1967. He was the 25th President of the United Nations General Assembly from 1970 to 1971. 122 delegations voted for Hambro with 2 votes against his candidacy.Milutin Tomanović (1971) Hronika međunarodnih događaja 1970, Institute of International Politics and Economics: Belgrade, p. 2497 (in Serbo-Croatian) He underlined that "peace, justice and progress" will be topics during his presidency in which he wanted to strengthen the organization. After his tenure as permanent representative ended, he continued serving the Ministry of Foreign Affairs and was the Norwegian ambassador in Geneva, to EFTA and various UN organizations. From 1976 he was the Norwegian ambassador to France. He also served on the United Nations International Law Commission from 1972. He died in 1977.
