CHICAGO – Now that Chicago is officially the U.S. bid city for the 2016 Summer Olympics, it must convince the International Olympic Committee that it deserves to stage the games.

Organizers were hopeful Tuesday that they could triumph over cities such as Rio de Janeiro, Tokyo and Madrid.

The U.S. Olympic Committee formally submitted Chicago as its bid in a letter last week to IOC President, Jacques Rogge, in advance of a Sept. 13 deadline. It was a formality because the USOC has worked with Chicago on its bid since choosing the city over Los Angeles in April.

“We look forward to working with the International Olympic Committee in convincing them why we believe Chicago is the best host city,” Mayor Richard Daley said while acknowledging “tough competition” from some of the “greatest cities in the world.”

The Czech capital of Prague officially entered the race Tuesday for the games, but its mayor acknowledged that the chances of winning are slim because another European city, London, is hosting the 2012 Olympics.

The IOC does not have a set policy of rotating the sites of the Olympics and is expected to announce a final list of applicant cities for the 2016 Games on Sept. 14. Madrid is considered a front-runner for 2016.

In Chicago, officials were upbeat about the success of an Olympics in a city enamored with its sports teams.

“This crazy sports town will pack venues and create an atmosphere that only Chicago can create,” said former Olympian, Mike Conley, executive director of World Sport Chicago, a new group focused on promoting amateur sports in the city.

In its letter to the IOC, the USOC stressed the compactness of a Chicago Olympics, with most venues and the athletes village situated in and around the city’s core.

The next step is for the city to submit an applicant questionaire to the IOC by Jan. 14, which is a detailed description of the organizers’ plans.

In June, the IOC will whittle the field to a short list and then select a host city in October 2009.