The International Olympic Committee's Coordination Commission made its fourth inspection of facilities in Rio and pointed especially to progress made in media villages, the venue master plan and recruitment of staff members by the local organizing committee.
Commission members spent three days in Brazil checking on preparations for the 2016 Games.
"We've seen solid progress this week," commission Chairman Nawal El Moutawakel said. "Building work is ongoing and the Organizing Committee continues to strengthen its capacity.
"However, many projects will have to be delivered simultaneously. We remain confident but we must all stay vigilant and continue to work hard, so that timelines are respected."
A release from the IOC said the next year is a critical for Rio organizers as work begins on a number of sports venues, which must be completed well ahead of the Aug. 5-16, 2016, Games to allow for test events at the sites.