Kuala Lumpur, July 29 (IANS): Organisers of the 2016 Rio Olympics face serious challenges over cleaning up the bay where sailing competitions will be held, International Olympic Committee (IOC) president Thomas Bach said here on Wednesday.

In recent months many concerns have been voiced over the safety of sailors competing on Guanabara Bay due to the high pollution level, especially after the Rio state government admitted it will not be able to meet its original target of reducing pollution in the bay by 80 percent, reports Xinhua.

"We have the issues which we discussed today again. The cleaning of the bay there were measures that have been presented and are two-fold: those which are starting already now and others which will be applied just before and during the Olympics to make sure that there is the safety and the health of the athletes," Bach said following the second day of the IOC executive board meeting.

"On the one hand we see great progress, on the other there is no time to lose. But given the fact that the organising committee has acknowledged its challenges, we are very confident we will have a great Games in one year because acknowledging challenges is the first and most important step to overcoming them."

Regarding Tokyo 2020, where the Japanese government has dropped the design for the new Olympic stadium due to rise in costs, Bach said the IOC would be involved from the start of the new design. The cancellation means the stadium will not be ready in time to host the final of the 2019 rugby World Cup.

"We have seen dramatic changes compared to the time of bidding by Tokyo - the construction costs for different reasons have just gone through the roof," said Bach.

"This is why we respect this decision and we are sure Tokyo will have a state-of-the-art stadium. We have also offered our support and our input when it comes to putting the tender together so we can be sure the interest of athletes and spectators are being taken into account from the very beginning of the planning."