- Director of the Library of the Romanian Academy (1950-1956);
- Counselor, Permanent Mission of Romania to the United Nations, New York (1956-1961);
- Deputy Minister of Foreign Affairs (1962-1970);
- Minister of Education (1970-1972);
- Ambassador to Switzerland and UN – Geneva (1980-1982);
- Ambassador to USA (1982-1984);
- Member of the Preparatory Committee of the World Conference on Population, Bucharest (1974) and of the World Conference on Science and Technology for Development, Vienna (1979), where he chaired the Committee on the Future of Science.
- President of the Futures Studies Commission of the Romanian Academy;
- Founding President of the Black Sea University Foundation and Professor of International Relations;
- Doctor Honoris Causa of the Cheboksary University, the Russian Federation;
- Doctor Honoris Causa of University of Oradea and of “Politehnica” University, Timişoara, Romania;
- Vice-President of the European Cultural Centre, Bucharest.
- Club of Rome (co-author of the Reports „No Limits to learning” – Pergamon Press, 1979 and „The Double Helix of Learning and Work”, CEPES, 2003;
- World Academy of Art and Science (WAAS);
- UNESCO – Comité du future;
- World Parliament of Cultures, Ankara;
- Académie Internationale de Prospective Sociale;
- Quantitative Group in IPSA;
- Word Future Studies Federation (WFSF);
- International Council for Science Policy.