BEIJING (AP) -- Jacques Rogge, president of the International Olympic Committee, acknowledged Wednesday that Beijing's air pollution could force the postponement of outdoor events during next year's Olympics.

"Yes, this is an option," Rogge told CNN in a brief interview. "It would not be necessary for all sports, sports with short durations would not be a problem. But definitely the endurance sports like the cycling race where you have to compete for six hours, these are examples of competitions that might be postponed or delayed to another day."

The statement from Rogge came just hours before Beijing was to celebrate the one-year mark in the countdown for next year's opening ceremony. A party in Tiananmen Square to celebrate the moment was to be attended by 10,000 people, including Chinese President Hu Jintao.

Beijing's filthy air and clogged traffic have worried Beijing organizers and the IOC, but this was Rogge's strongest statement on the subject and was sure to embarrass local organizers.

Beijing officials have spent billions of dollars closing factories and moving others out of town, but nonstop construction and booming car sales have made air quality even worse.

Beijing Olympic organizing officials refused to comment on Rogge's statement. The media relations office said rules prevented spokesmen from answering questions over the telephone. The director of Olympic cycling events was in a meeting and not immediately available to comment.