Hans Klemm served as the U.S. Ambassador to Timor-Leste from 2007 to 2010. Previously, he served as Minister Counselor for Economic Affairs at the U.S. Embassy in Tokyo, responsible for all aspects of bilateral and multilateral economic policy with Japan. Earlier, Mr. Klemm worked as Director of the Office of Career Development and Assignments in the Bureau of Human Resources of the Department of State in Washington, D.C., where he managed the assignment process and career development programs for Foreign Service employees. He also served as the Director of the Office of Agriculture, Biotechnology and Textile Trade Affairs in the Bureau of Economic and Business Affairs. Overseas, Mr. Klemm worked at U.S. embassies in Bonn, Seoul and Port of Spain. In his foreign and domestic assignments, he has had responsibility for a broad range of management and international economic policy issues, including bilateral and multilateral trade, international finance and development, international organization affairs, and civil aviation.

Mr. Klemm joined the Foreign Service of the U.S. Department of State in September 1981 and was promoted into the Senior Foreign Service in January 2001. He is a graduate of the Senior Seminar, a management and leadership training program hosted by the Department of State for senior representatives of U.S. agencies responsible for national security. In 1993 and again in 2000, he was awarded the Department of State's Superior Honor Award. Mr. Klemm speaks Japanese and German and was graduated from Stanford University (MA, International Development Policy) and Indiana University (BA, Economics and History).