London: IAAF chief Lord Sebastian Coe believes Russia is showing a significant change in its attitude to tackling the doping scandal that saw the nation exiled from world athletics.
Russia has been banned from international athletics competition since November 2015 after doping issues.
The country's anti-doping agency, RUSADA, is also yet to be declared fully compliant by the World Anti-Doping Agency.
Russian athletes have also effectively been banned from next year's Winter Olympics in Pyeongchang, unless they can satisfy stringent drug-testing regulations in order to compete as neutrals.
Coe indicated there are reasons for hope that Russia is finally dealing with the problem, but he said the IAAF would still resist setting any time-scale for the nation's reintegration into athletics.
"We made a decision that in a way was quite different to the one the IOC was confronted with," Coe told BBC Radio Five Live on Sunday. "I've had 149 or 150 positive tests in the sport, from Russia within a three or four year period."