The Department of Political and Peacebuilding Affairs (DPPA) is the principal support structure for peacemaking and preventive diplomacy efforts. The Department provides support to numerous envoys of the Secretary-General engaged in peace talks or crisis diplomacy, while overseeing more than a dozen field-based United Nations special political missions with mandates to help nations and regions resolve conflicts and tensions peacefully. Of these missions, regional offices covering Central Africa, West Africa and Central Asia have explicit mandates for preventive diplomacy and strengthening the capacity of states and regional actors to manage sources of tension peacefully.

There are currently 11 peacekeeping operations led by the Department of Peace Operations (DPO). UN Peacekeeping helps countries navigate the difficult path from conflict to peace. They have unique strengths, including legitimacy, burden sharing, and an ability to deploy troops and police from around the world, integrating them with civilian peacekeepers to address a range of mandates set by the UN Security Council and General Assembly.

The Department of Operational Support (DOS) oversees one support mission, the United Nations Support Office in Somalia (UNSOS).