Sujiro Seam joined the Ministry of Foreign Affairs in 1998. He started his diplomatic career as a member of the legal directorate, representing the French Government before the European court of justice and providing legal advice on European and international
economic law. At the same time, he was appointed legal adviser of the French Delegation to the intergovernmental Commission for the Channel Tunnel.
In 2001, he moved to Brussels, working as a national expert in the World Trade Organisation Dispute Settlement Unit of the Directorate General for Trade in the European Commission. In 2004, he joined the Permanent Representation of France to the European Union, as Counsellor in charge of fisheries, regional policy, outermost regions, overseas countries and territories and maritime affairs. In this capacity he chaired the working parties on these matters under the French Presidency of the European Union in 2008.
In 2009, he returned to the Ministry of Foreign Affairs in Paris, where he served as Deputy Assistant Secretary for food security and economic development. In this capacity, he chaired the meetings on food security under the French Presidency of the G8/G20 in 2011. He was promoted Principal Deputy Assistant Secretary for Global Public Goods in 2011 and then for Development and Global Public Goods in 2013. During these years in the Headquarters, he was in charge of the preparation of the Ministerial Conference of the 6th World Water Forum in Marseille in 2012 and led the French Delegation to the Development Working Group of the G20.
Sujiro Seam was appointed Consul General of France in Houston on 17 June 2013.