RIO DE JANEIRO (AFP) - Olympics chief Thomas Bach has admitted that preparations for the Rio Games had been "challenging" as the clock ticks down to this week's opening ceremony.
Revelations of Russia's state-organised doping regime have rocked the Games in recent days, following political and economic upheaval in Brazil and concerns over the Zika virus.
"It has been a long and testing journey to get to this point," Bach told delegates as he opened an International Olympic Committee session in Rio on Monday.
"It is no exaggeration to say that the Brazilians have been living through extraordinary times. The political and economic crisis in the country is unprecedented," he added.
"It goes without saying that this situation has made the final preparations for the Olympic Games challenging."
Brazil's President Dilma Rousseff was suspended in May and will face an impeachment trial for alleged violations of budgeting rules from Aug 29, eight days after the Games close.
Bach also defended the IOC's decision not to ban Russia outright from Rio after revelations of a vast doping cover-up involving the sports ministry and secret service.
The IOC instead left it up to individual sports bodies to ban or allow Russian athletes, making the eventual make-up of the Russian team unclear.
"You cannot punish a human being for the failures of his or her government if he or she is not implicated. These principles are now being implemented," Bach said.
"This decision is about justice. Justice has to be independent from politics. Whoever responds to a violation of the law with another violation of the law is destroying justice."
The IOC session will conclude on Thursday, a day before Friday's opening ceremony at the Maracana stadium.