Assistant Secretaries-General

Thomas Gass


Thomas Gass was appointed by the Secretary-General as Assistant Secretary-General for Policy Coordination and Inter-Agency Affairs in UN DESA and he took office on 3 September 2013. He brings with him wide-ranging experience in bilateral and multilateral development cooperation. From 2009 to 2013, he 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, and ensured the delivery of a development cooperation programme of up to 33 million dollars a year. He also chaired the Donors of the Nepal Peace Trust Fund, the main instrument for international support to Nepal’s peace process.

Before his posting to Nepal from 2004 to 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) and its subsidiary bodies, 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.

Born in 1963, Thomas Gass holds a PhD in natural sciences from the Swiss Federal Institute of Technology in Zurich and a MSc and engineering diploma in agricultural sciences from the same Institute.


Lenni Montiel

Mr. Lenni Montiel is Assistant Secretary-General for Economic Development in UN DESA.

Mr. Montiel has held strategic positions within the Government of Venezuela and in several international organizations, systematically involved in policy making and analytical work on issues related to economic and social development.

He shares his current responsibilities in UN DESA, also with the representation of the UN and of the Secretary-General to the G20 Meetings, as Sherpa. Mr. Montiel was previously Director of Economic, Social and Development Affairs in the Executive Office of the Secretary-General Mr. Ban Ki-Moon. He was United Nations Resident Coordinator and UNDP Resident Representative in Turkmenistan. He worked for several years as Senior Global Policy Adviser on Governance in UNDP, from where he performed different assignments around the globe.

Mr. Montiel was also Technical Assistant to the Director for Venezuela and Panama at the Executive Board of Directors of the Inter-American Development Bank in Washington, DC in the USA.

In Venezuela Mr. Montiel worked as Director of Social Policy in the Ministry of Planning and Director of Planning in the Ministry of Family and Social Affairs. He was also a member of the team that established the Social Investment Fund of Venezuela, and as such led the negotiation of the first ever loans for Venezuelan social sectors by the World Bank and the Inter-American Development Bank.

Mr. Montiel was trained as Economist and got a Master of Sciences in Economics from the Belorussian Institute of National Economic Planning (former USSR), a Master of Arts on Legislative Affairs from the University of Hull (UK) and a PhD in Public Policy from the University of Birmingham (UK).

Mr. Montiel has been a member of the academic staff at the Erasmus University, Institute for Housing and Urban Development Studies in Rotterdam, The Netherlands; and also at the Central University of Venezuela, School of Political and Administrative Sciences.

Mr. Montiel speaks Spanish, English and Russian.


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