IOC head Thomas Bach visits the Olympic cauldron in Rio de Janeiro, Brazil on July 27, 2016. [Photo/Xinhua]

In a gesture of goodwill, Paes presented the head of the Australian delegation, Kitty Chiller, with the keys to the city of Rio on Wednesday and thanked her for her understanding.

Paes, who had downplayed the complaints by saying he might give the Australians a kangaroo to make them feel at home, apologized and said he would support Australia as his second team.

The build-up to the Games was marked by concerns over a budget crisis in Rio de Janeiro, sparked by Brazil's worst recession since the 1930s, as well as an outbreak of the Zika virus, and a political crisis that has seen suspended President Dilma Rousseff placed on trial in the Senate.

Aside from fears over pollution in Guanabara bay where sailing and long-distance swimming events will be held, some infrastructure for the Games is being completed at the last minute.

The metro line to carry visitors from the centre of Rio to the distant western neighbourhood of Barra da Tijuca where the Games will be held will only be inaugurated on Saturday by interim President Michel Temer.

Paes told a news conference the city would benefit from the legacy of the Games, which had allowed the completion of long-delayed projects. Visitors, he said, "will not find a perfect city but a much better one than we had in 2009."