(k) The duty of a State, in the conduct of its international relations in the economic, social, technical and trade fields, to refrain from measures which would constitute interference or intervention in the internal or external affairs of another State, thus preventing it from determining freely its political, economic and social development; this includes, inter alia, the duty of a Stat~ not to use its external economic assistance programme or adopt any multilateral or unilateral economic reprisal or blockade and to prevent the use of transnational and multinational corporations under its jurisdiction and control as instruments of political pressure or coercion against another State, in violation of the Charter of the United Nations;