Several regional organizations and arrangements are beginning to play a significant role in cooperation with the United Nations, especially in the field of peacekeeping. In 1997, the Security Council authorized the continuation of the presence of an 800-man force stationed in the Central African Republic to implement the Bangui Agreements, known as MISAB and composed of personnel fielded by seven countries. In March 1998, the Security Council decided that MISAB would be replaced by the UN Mission in the Central African Republic (MINURCA). In almost every recent African conflict that has led to a peacekeeping mission, the Organization of African Unity (OAU) has sought to reinforce the UN role, often by extending support to the peacemaking process.

In Bosnia and Herzegovina, UNMIBH works in close cooperation with the High Representative of the European Union, with the North Atlantic Treaty Organization (NATO)-led Force, and with the Organization for Security and Cooperation in Europe (OSCE). In Georgia, UNOMIG works in close cooperation with the OSCE and the peacekeeping force of the Commonwealth of Independent States (CIS).

In Kosovo, where an armed NATO force ensures overall security, a massive international effort is under way to turn the war-devastated Territory into a functioning democratic society. Four international organizations and agencies are working together in one operation under the leadership of the Special Representative of the Secretary-General. The United Nations itself is responsible for civil administration; humanitarian assistance is led by the Office of the UN High Commissioner for Refugees; democratization and institution-building are directed by the Organization for Security and Cooperation in Europe; and economic reconstruction is managed by the European Union.