Thomas Gass was appointed by the Secretary-General as Assistant Secretary-General for Policy Coordination and Inter-Agency Affairs in UN DESA and took office on 3 September 2013.

From 2009 to 2013, Thomas Gass served as Head of the Mission of Switzerland to Nepal (Ambassador and Country Director of the Swiss Agency for Development and Cooperation), where he established the Embassy of Switzerland in Nepal. He also chaired the Donors of the Nepal Peace Trust Fund. Before, from 2004-2009, Mr Gass was Head of the Economic and Development Section at the Permanent Mission of Switzerland to the UN in New York, where he represented Switzerland’s interests, in particular in the Economic and Social Council (ECOSOC), its subsidiary Commissions, the General Assembly and the Executive Boards of the major UN Funds and Programmes. During this time, Mr Gass was the Chair of the Donor Group of the UN Global Compact. In 2006, he was the Vice-President for Western European and Other Group (WEOG) of the Commission on Population and Development, and in 2008 he was the Vice-President (WEOG) of the Executive Board of UNDP/UNFPA. In 2007, he successfully facilitated the landmark TCPR/QCPR Resolution, the periodic review of the General Assembly operational system for development.

Mr Gass also served as Policy and Programme Officer for the Swiss Agency for Development and Cooperation, as Deputy Resident Representative of the United Nations Development Programme (UNDP) in Guyana, and as Regional Director for Europe with the International Plant Genetic Resources Institute in Rome.