Rio de Janeiro Mayor Eduardo Paes has said that the Brazilian city will not be able to clean the polluted bay where Olympic sailing competitions will be held before the 2016 Games.
Brazil had made a commitment to reduce pollution in the Guanabara Bay by 80%.
But Mr Paes admitted that the target would not be met.
He regretted the missed opportunity but told the AP news agency that the pollution didn't pose a risk to the health of athletes.
Olympic sailors who visited Rio de Janeiro recently described the bay as an open sewer.