Burundi is a landlocked country in the Great Lake regions of Eastern Africa. Neighboring countries include Rwanda, Tanzania, and Democratic Republic of the Congo. Burundi is hilly and mountainous with access to Lac Tanganyika. The government system is a republic; the chief of state and head of government is the President. Burundi has a traditional economic system in which the allocation of available resources is made on the basis of primitive methods and many citizens engage in subsistence agriculture. Burundi is a member of the African Union (AU), African Economic Community (AEC) and Common Market for Eastern and Southern African (COMESA).