An   ambassador  is the President’s highest-ranking representative to a specific nation or international organization abroad. An effective  ambassador  has to be a strong leader—a good manager, a resilient negotiator, and a respected representative of the United States. A key role of an   ambassador  is to coordinate the activities not only of the Foreign Service Officers and staff serving under him, but also representatives of other U.S. agencies in the country. At some overseas posts, personnel from as many as 27 federal agencies work in concert with   embassy  staff.