House Committee on International Relations
http://wwwc.house.gov/international_relations/
This is the House Committee with jurisdiction over matters including relations with foreign nations, embassies, national border lines, exports, foreign loans, international conferences, international education, declarations of war, the American National Red Cross, and the United Nations.

Senate Committee on Foreign Relations
http://foreign.senate.gov/
Areas of jurisdiction of the Senate Committee on Foreign Relations include acquisition of land and buildings for embassies, the international activities of the American National Red Cross, international aspects of nuclear energy, the International Monetary Fund, intervention abroad and declarations of war, the protection of United States citizens abroad and expatriation, the United Nations and its affiliated organizations, and the World Bank group.