Ambassador Sugiyama presented his credentials as Ambassador to the United States in March 2018. His diplomatic career with the Japanese Ministry of Foreign Affairs spans more than 40 years. He most recently served as Vice-Minister for Foreign Affairs. Previous positions include Deputy Director-General of the Middle Eastern and African Affairs Bureau as well as the International Cooperation Bureau; Director-General for Global Issues, including Ambassador for Climate Change; and Director-General of the Asian and Oceanian Affairs Bureau.
Ambassador Sugiyama has also held leadership positions within the Foreign Policy Bureau and Treaties Bureau of the Ministry of Foreign Affairs. His overseas assignments have included multiple positions at the Embassy of Japan in Washington, D.C.; Political Minister at the Embassy of Japan in Korea, and Deputy Chief of Mission at the Embassy of Japan in Egypt. He entered the Ministry of Foreign Affairs in 1977.