After entering the Ministry of Japan's Foreign Affairs in 1970, Ambassador Tsuneo Nishida occupied positions in various countries: as First Secretary at the Embassy of Japan in the Union of Soviet Socialist Republics, as Counsellor at the Embassy of Japan in the United States of America, and as Consul-General of Japan in Los Angeles.
Furthermore, he served as Deputy Director-General of the European and Oceanic Affairs Bureau and as Director-General of the Economic Cooperation Bureau in Tokyo. In 2002, Ambassador Nishida was appointed Deputy Vice-Minister of Foreign Policy and Director-General of the Foreign Policy Bureau. From 2005 to 2007, he was the Deputy Minister for Foreign Affairs.
In June 2010, Ambassador Nishida was appointed Ambassador Extraordinary and Plenipotentiary, Permanent Representative of Japan to the United Nations and prior to that he served as Ambassador Extraordinary and Plenipotentiary at the Permanent Mission of Japan to Canada.