The IOC's coordination commission made its eighth visit to Brazil this week and reported that venues are taking shape even as organizers begin with ticketing and volunteer training.
Still, officials warned, there is much to be done.
Organizers are "now entering the most intense phase in the preparation for the Games, as they reach a new level of detail while planning numerous test events," said Nawal El Moutawakel, the commission's chairwoman.
The golf course, velodrome and equestrian venues face pressing deadlines in the coming months. Accommodations and transportation are also a concern.