In a joint letter to the UN Secretary-General sent just prior to unification, the Ministers of Foreign affairs of North and South Yemen stated that "All treaties and agreements concluded between either the Yemen Arab Republic or the People's Democratic Republic of Yemen and other States and international organizations in accordance with international law which are in force on 22 May 1990 will remain in effect, and international relations existing on 22 May 1990 between the People's Democratic Republic of Yemen and the Yemen Arab Republic and other States will continue."Bühler, Konrad (2001). State Succession and Membership in International Organizations. Martinus Nijhoff Publisher. ISBN9041115536.