The new International Olympic Committee president Thomas Bach says his organisation would be prepared to ban any country from the Olympics if they have a below-standard doping programme.
Track stars Jamaica and Kenya appear the most in danger from any national sanctions.
Any use of such stringent sanctions would have to be agreed by the World Anti-Doping Agency, who are holding a conference in Johannesburg.
Bach, who replaced Jacques Rogge as Olympic chief in September, is there - and he says they need to use the greatest possible deterrents available.
The IOC president is strongly urging delegates at the WADA conference to back the revised anti-doping code's more stringent punishments - this week the new code will be ratified that doubles bans for intentional doping culprits from two to four years - automatically excluding them from the next Olympics.
Tests for banned substances will be more stringent than ever for the 2014 Winter Olympics in Russia.
Athletes will undergo 1,269 pre-competition tests - over 400 more than the Vancouver Games - while total tests at Sochi will increase by almost 300 to 2,453.