The Cook Islands are a member of multilateral organizations and have diplomatic ties with a variety of nations. The Cook Islands adhere to treaty obligations and "interacts with the international community as a sovereign and independent state" despite being in free association with New Zealand, which has the "delegated authority to assist the Cook Islands" in foreign affairs.
The Cook Islands joined a number of specialized United Nations organizations in the 1980s: the Food and Agriculture Organization and UNESCO in 1985, the International Civil Aviation Organization in 1986, and the World Health Organization in 1984. According to the Repertory of Practice of United Nations Organs, New Zealand made the declaration "that its future participation in international agreements would no longer extend to the Cook Islands..." in 1988. In 1991, the Cook Islands became full members of the Intergovernmental Negotiating Committee for a Framework Convention on Climate Change (INC) and the United Nations Conference on Environment and Development (UNCED). The Repertory of Practice describes this as "further evidence that the international community had accepted the Cook Islands as a “State” under international In 1992, the United Nations Secretariat "recognized the full treaty-making capacity of the Cook Islands," and the Secretary-General made the decision that the Cook Islands could participate in treaties that were open to "all states" in his capacity as the depository of multilateral treaties.