The Bureau exercises supervision over all international exhibitions of non-commercial character (other than fine arts exhibitions), with a duration of more than three weeks, which are officially organised by a nation and to which invitations to other nations are issued through diplomatic channels.

The city to host the EXPO 2012 will be elected in a secret ballot by delegates of 98 states during General Assembly of the International Exhibitions Bureau (BIE)

GEOGRAPHICAL REGIONS	BIE MEMBER STATES
Europe (31 states)	Andorra, Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Finland, France, Greece, Spain, Holland, Iceland, Malta, Monaco, Germany, Norway, Poland, Portugal, Romania, San Marino, Slovakia, Slovenia, Switzerland, Sweden, Turkey, Ukraine, Hungary, Great Britain, Italy
Middle East (8 states)	Iran, Israel, Yemen, Jordan, Qatar, Lebanon, Oman, United Arab Emirates
Africa (14 sates)	Algeria, Equatorial Guinea, Madagascar, Morocco, Mauretania, Namibia, Nigeria, RSA, Senegal, Seychelles, Tanzania, Togo, Tunisia, Uganda
Asia and Oceania (15 states)	Bangladesh, China, Indonesia, Japan, Cambodia, Korea, Laos, Malaysia, Mongolia, Thailand, Vietnam, Australia, Philippines, Nauru, Palau
Former USSR countries (5 states)	Byelorussia, Kazakhstan, Kyrgyzstan, Russia, Uzbekistan
Caribbean (11 states)	Antigua and Barbuda, Bahamas, Barbados, Dominicana, Grenada, Haiti, Cuba, Saint Kitts and Nevis, Saint Lucia, Saint Vincent and the Grenadines, Trinidad and Tobago
Central and South America (13 states)	Argentina, Brazil, Guyana, Columbia, Peru, Surinam, Uruguay, Venezuela, Belize, Costa Rica, Mexico, Nicaragua, Salvador
North America	Canada