The International Olympic Committee President Jacques Rogge said yesterday Beijing was running out of time to tackle air pollution that could undermine the success of next year's Olympic Games.

Speaking at the opening of the 7th World Conference on Sport and Environment, Rogge said some endurance events at the 2008 Games may have to be rescheduled because of poor air quality.

"Despite all these efforts, time may be running out, and the conditions required for the athletes competing in endurance disciplines might not be met 100 percent on a given day," he said.

"For this reason, we may have to reschedule some events so that the health of athletes is scrupulously protected."

Earlier yesterday, the United Nations Environment Program (UNEP) congratulated Beijing on the 12-billion-dollar clean-up that has been taking place since it won the right to host the Games in 2001.

Beijing had pledged to stage a "green" Olympics and had already achieved most of its environmental goals, the UNEP said in a report.

But the report stressed that poor air quality would not be resolved in time for the Games.

Short period

"Improvements in air quality cannot be achieved in a short period of time," said Eric Falt, the UNEP's sport and environment program director. "Air quality, therefore, remains a legitimate concern for the competitors and for the citizens of Beijing themselves."

But the IOC's chief inspector for the 2008 Games, Hein Verbruggen said they were confident that the issue can be "adequately addressed" when speaking at a press conference after the IOC coordination commission ended a three-day inspection of Beijing's preparations.

"The issue of the air quality remains a concern. But it's a joint concern, not only for us on behalf of the athletes but also for Beijing Organizing Committee for the Olympic Games (BOCOG)," Verbruggen said.

Verbruggen said that the IOC had been well aware of the air pollution issue as early as seven years ago when Beijing was bidding for the Games and since then the issue had been extensively addressed.

"We can only say that six years later, they (BOCOG) lived up to their commitments," he said. "There is, as far as we are concerned, no blame to be addressed on BOCOG."