Track and field's ruling IAAF has called on the World Anti-Doping Agency (WADA) to impose stronger penalties for drug offences, including a four-year ban for serious first-time violations.

"We want a minimum of four years for certain substances," International Association of Athletics Federations President Lamine Diack told reporters on Thursday.

"If possible, we'll take our own measures if we find it necessary to impose four-year sanctions."

WADA currently has a two-year penalty for serious violations by initial offenders.

The agency is reviewing its anti-doping code and will adopt a revised one in November, although it is unlikely to approve the changes sought by the IAAF.

Diack insisted, meanwhile, that the IAAF was doing everything possible to win the battle against drug cheats.

"Nobody will get off scot-free if they win a gold medal by illegal means," he said. "There are cheats out there but we are doing everything we can to catch them."

Diack defended the IAAF's stance on doping following its congress ahead of the world championships beginning in Osaka on Saturday.

"We complied with the International Olympic Committee to reduce bans to two years but we consider two years an absolute minimum," he said.

"Other sports want to take that two-year figure down to a year or six months. We feel it is possible to seek more than two years -- we can apply three or four in some cases.

"Some of our athletes are tested four to eight times a year. If we were convinced the sport was populated with drug cheats we would call it quits."

Diack added: "With WADA governments are involved. The main battle now is to make sure national federations also screen their athletes as we do."