"People who arrive in Brazil imagining they're in England or who arrive in Rio imagining they're in London will have a frustrating experience in terms of development," Mayor Eduardo Paes said at the launch of the TV broadcast center for the World Cup, which opens in 10 days.
"I don't doubt Brazil is better than England and Rio de Janeiro better than London," he quickly added.
Some of Rio's less flattering traits greet visitors soon after arrival, including highly visible shantytowns, long traffic jams and patchy mobile communications.
Like the other 11 World Cup host cities, it has struggled to finish the infrastructure promised for the tournament, and many projects have been shelved.
"Rio is a city that doesn't hide its poorest people like other places," said Paes.
But Brazil, he said, is a country that "in the last decade has removed 30 million people from poverty and is undergoing a fantastic transformation."
Rio will host seven World Cup matches including the final on July 13.
It is also battling delays in preparing for the Summer Olympics. In April, International Olympic Committee vice-president John Coates criticized organizers' preparations for the games as "the worst that I've ever experienced."
Paes said last August it was "a shame" Brazil was hosting the Olympics because it lacks the government policy needed to capitalize on major sports events.