<span>The Organization of American States (OAS or OEA) was founded April 30, 1948, with its headquarters located in Washington DC. It was created to establish and promote democracy, human rights, economic and military cooperation among it's members. The list of members include all the states in the United States of America as well as the following: Bahamas, Bolivia, Antigua and Barbuda, Chile, Canada, Argentina, Cuba, Peru, Mexico, Barbados, Ecuador, Haiti, Guyana, Belize, Brazil, Grenada, Colombia, Trinidad and Tobago, Costa Rica, Saint Vincent and the Grenadines, Venezuela, Dominica, Dominican Republic, Nicaragua, Panama, El Salvador, Guatemala, Jamaica, Honduras, Paraguay, Peru, Saint Lucia, Suriname, St. Kitts and Nevis, Uruguay.</span>
I believe the answer is <span>the independent states of the Americas By Americas, it refers to the whole continent, not just united states. These organizations was created to create multilateral relationship between these nations to ensure political cooperation and easier movements of materials and products.</span>
The hint in the question is that the city major will attend the ceremony- this tells you that the ceremony will have a more representative, formal character, and will not be an internal celebration among people who know each other (this would make it informal or semi-formal).