The Geneva Protocol of 1925 was drawn up and signed at the conference for the supervision of the international trade in arms and ammunition, which was held in Geneva under the auspices of the League of Nations from 4 May to 17 June 1925. The conference adopted a convention for the supervision of the international trade in arms, munitions and implements of war which has not entered into force and, as a separate document, a protocol on the use of gases. The earlier treaties prohibiting the use of gases to which the protocol refers are in particular the Hague Declaration concerning asphyxiating gases of 29 July 1899 and the Treaty of Versailles of 28 June 1919 as well as the other peace treaties of 1919. Article 171 of the Treaty of Versailles provides: "The use of asphyxiating, poisonous or other gases and all analogous liquids, materials or devices being prohibited, their manufacture and importation are strictly forbidden in Germany."( See also Article 5 of the Treaty of Washington of 6 February 1922 and the note introducing the Hague Declaration (IV,2) of 1899.) The United Nations General Assembly has adopted several resolutions in which it calls for strict observance by all states of the principles and objectives of the Geneva Protocol of 1925, condemns all actions contrary to those objectives and invites all states to accede to the Protocol (resolutions 2162 B (XXI) of 5 December 1966, 2454 A (XXIII) of 20 December 1968, 2603 B (XXIV) of 16 December 1969, and 2662 (XXV) of 7 December 1970). Resolution 2603 A (XXIV) of 16 December 1969 gives an interpretation of the Geneva Protocol of 1925.