In response to a request from the Secretary-General, countries may volunteer personnel, equipment, supplies or other support for a peacekeeping mission. Countries providing these essential elements are reimbursed from the mission budget at agreed rates. Contributing personnel to peacekeeping is not obligatory; a troop-contributing country retains the right to withdraw its personnel from an operation. In addition, many countries have voluntarily made additional resources available to support UN peacekeeping efforts on a non-reimbursable basis in the form of transportation, supplies, personnel and financial contributions, above and beyond their asssessed share of peacekeeping costs.

For decades, States have recognized the unique advantages of UN peacekeeping as a means of dealing with conflicts. Its universality makes it uniquely suited to a wide range of situations, and assures a legitimacy as action taken on behalf of a global organization rather than on the basis of national or regional interests. UN peacekeeping can also help focus global attention, promote coordination and burden-sharing among those seeking to advance peace from outside a conflict area.