Olympic organisers are meeting in China six days before the Beijing Games, amid ongoing concerns about air pollution, internet restrictions and doping.
International Olympic Committee (IOC) President Jacques Rogge arrived in Beijing amid a row over internet access for foreign journalists, reported BBC.
Lingering concerns about air quality are also hampering final preparations.
The IOC has also stripped the US 4x400m men's relay team of gold at the Sydney Games in 2000 after a doping admission.
Sprinter Antonio Pettigrew admitted in June that he used banned substances between 1997 and 2003.
And a once-banned Greek athlete has threatened to sue the IOC chief if she is not allowed to compete.
Greek sprinter Katerina Thanou pulled out of the Athens Olympics in 2004 after failing to report for a drugs test - her third missed test - and was banned for two years.
She is now in Greece's Olympic athletic team for Beijing, but Mr Rogge has suggested she could now be barred from competing.
The BBC's Alex Capstick, in Beijing, says leading members of the IOC are keen to know why politically-sensitive websites were blocked - despite a promise that foreign reporters covering the Games would be given complete access to the web.
Access restrictions appear to have been eased in recent days, but the clamour was only slightly dampened by a rare press conference given by Chinese President Hu Jintao.
Mr Hu appealed to the international media not to "politicise" the Beijing Games
Air pollution also remains a big problem.
The Chinese authorities have been working on improving the dirty air that hangs over Beijing, but athletes remain concerned.
Steve Roush, head of sports performance with the United States team, said he is monitoring the situation and is optimistic.
"We do have fallback plans if all of a sudden it deteriorates to the point where the health and safety of our athletes might be in jeopardy," he said.
"But I don't think that if the air quality was at that level that the IOC would even allow for the competition to take place."
The IOC was going to discuss whether to allow Katerina Thanou to compete at the Games, but it seems a final decision has been delayed until next Thursday.
She was one of two Greek sprinters involved in a drug scandal that completely dominated the start of the 2004 Olympics in Athens.
She withdrew from those Games and has since served a two-year doping ban given to her by the International Association of Athletics Federations (IAAF).
But the IOC has reserved the right to consider her eligibility for these Games.
Ms Thanou's lawyer has threatened to sue the IOC if she is barred from competing.
The matter is muddied by the reallocation of the medals won by Marion Jones at the 2000 Olympics in Sydney.
The American athlete has returned her three gold and two bronze medals after admitting she had been taking banned substances.
One of her titles came in the 100m and the IOC must decide whether to promote the second placed runner instead - and that is Katerina Thanou.