Unit - wait
- unit tactical training
- United Nations
- United Nations Conference on Trade and Development
- United Nations Economic Commission for Europe
- United Nations Educational Programme
- United Nations Educational, Scientific and Cultural Organisation
- United Nations Environment Programme
- United Nations High Commissioner for Refugees
- United Nations Interim Administration Mission in Kosovo
- United Nations Liaison Office
- United Nations Office for the Coordination of Humanitarian Affairs
- United Nations Office of the High Commissioner for Refugees
- United Nations Protection Force
- United Nations Security Council
- United States of Europe
