Brazil's President Dilma Rousseff has received the Olympic flag, as the competition's world governing body warned the country has to "work harder" ahead of the Rio Games in 2016.
Rio Mayor Eduardo Paes flew into Rio de Janeiro from London with the flag yesterday, marking the official handover of the Games.
The country won a total of 17 medals at the London Olympics that concluded over the weekend - three gold, five silver and nine bronze.
International Olympic Committee president Jacques Rogge meanwhile has warned that much remained to be done to prepare for the Rio Games.
The city of 6.5 million is notorious for its huge traffic jams, poor infrastructure and slum violence, but authorities insist Rio will deliver.
Brazil insists everything will be ready for the first summer Olympics to be held in South America.
Some of the venues will be used for the 2014 World Cup, but the Olympic Village and other event sites have yet to be built.