word | | Country name |
| Tuvalu | Tuvalu | conventional long form: none conventional short form: Tuvalu local long form: none local short form: Tuvalu former: Ellice Islands note: "Tuvalu" means "group of eight," referring to the country's eight traditionally ... |
| UAE | United Arab Emirates | conventional long form: United Arab Emirates conventional short form: none local long form: Al Imarat al Arabiyah al Muttahidah local short form: none former: Trucial Oman, Trucial States abbreviation: UAE |
| Ubangi | Central African Republic | conventional long form: Central African Republic conventional short form: none local long form: Republique Centrafricaine local short form: none former: Ubangi-Shari, Central African Empire abbreviation: CAR |
| Uganda | Uganda | conventional long form: Republic of Uganda conventional short form: Uganda |
| UK | United Kingdom | conventional long form: United Kingdom of Great Britain and Northern Ireland; note - Great Britain includes England, Scotland, and Wales conventional short form: United Kingdom abbreviation: UK |
| Ukraine | Ukraine | conventional long form: none conventional short form: Ukraine local long form: none local short form: Ukrayina former: Ukrainian National Republic, Ukrainian State, Ukrainian Soviet Socialist Republic |
| Ukrainian | Ukraine | conventional long form: none conventional short form: Ukraine local long form: none local short form: Ukrayina former: Ukrainian National Republic, Ukrainian State, Ukrainian Soviet Socialist Republic |
| Ukrayina | Ukraine | conventional long form: none conventional short form: Ukraine local long form: none local short form: Ukrayina former: Ukrainian National Republic, Ukrainian State, Ukrainian Soviet Socialist Republic |
| Uls | Mongolia | conventional long form: none conventional short form: Mongolia local long form: none local short form: Mongol Uls former: Outer Mongolia |
| Uman | Oman | conventional long form: Sultanate of Oman conventional short form: Oman local long form: Saltanat Uman local short form: Uman former: Muscat and Oman |
| Umbuso | Swaziland | conventional long form: Kingdom of Swaziland conventional short form: Swaziland local long form: Umbuso weSwatini local short form: eSwatini |
| UN | Macedonia | ... local long form: Republika Makedonija local short form: Makedonija note: the provisional designation used by the UN, EU, and NATO is the Former Yugoslav Republic of Macedonia (FYROM) former: People's Republic ... |
| Unidos | Mexico | conventional long form: United Mexican States conventional short form: Mexico local long form: Estados Unidos Mexicanos local short form: Mexico |
| Union | Burma | conventional long form: Union of Burma conventional short form: Burma local long form: Pyidaungzu Myanma Naingngandaw (translated by the US Government as Union of Myanma and by the Burmese as Union of ... |
| Union | Comoros | conventional long form: Union of the Comoros conventional short form: Comoros local long form: Union des Comores local short form: Comores |
| Union | South Africa | conventional long form: Republic of South Africa conventional short form: South Africa former: Union of South Africa abbreviation: RSA |
| United | Cameroon | ... Cameroon conventional short form: Cameroon local long form: Republique du Cameroun/Republic of Cameroon local short form: Cameroun/Cameroon former: French Cameroon, British Cameroon, Federal Republic of Cameroon, United Republic of Cameroon |
| United | Egypt | conventional long form: Arab Republic of Egypt conventional short form: Egypt local long form: Jumhuriyat Misr al-Arabiyah local short form: Misr former: United Arab Republic (with Syria) |
| United | Mexico | conventional long form: United Mexican States conventional short form: Mexico local long form: Estados Unidos Mexicanos local short form: Mexico |
| United | Syria | conventional long form: Syrian Arab Republic conventional short form: Syria local long form: Al Jumhuriyah al Arabiyah as Suriyah local short form: Suriyah former: United Arab Republic (with Egypt) |
| United | Tanzania | conventional long form: United Republic of Tanzania conventional short form: Tanzania local long form: Jamhuri ya Muungano wa Tanzania local short form: Tanzania former: United Republic of Tanganyika and Zanzibar |
| United | United Arab Emirates | conventional long form: United Arab Emirates conventional short form: none local long form: Al Imarat al Arabiyah al Muttahidah local short form: none former: Trucial Oman, Trucial States abbreviation: UAE |