Monaco - The IAAF on Friday extended the ban on Russia from international competition, raising fears that the athletics powerhouse might miss out on the Rio Olympics.
A five-strong IAAF taskforce led by Norwegian Rune Andersen, a former director of the World Anti-Doping Agency (WADA), presented a report to the Sebastian Coe-headed IAAF Council, which administers the affairs of the International Association of Athletics Federations.
Andersen said that Russia had showed "considerable progress" in the wake of its suspension in November.
"However, the view of the taskforce is that there is significant work still to be done to satisfy reinstatement conditions."
But a door was left ajar to allow Russia's participation in Rio: the IAAF will hold an extraordinary Council meeting in May during which Andersen will again present his taskforce's update on Russia's progress.
"My job is not actually to get as many athletes to the Olympic Games as possible. The job of the Council is to make sure that those athletes who are going to the Olympics are clean and are in systems that are based upon integrity," Coe said.
"There were no preordained outcomes today. We wanted to hear what Rune and the team had to say and we were unanimously satisfied that more work needed to be done before we could ultimately make a decision (on Russia's reinstatement)."
Coe said Russia's Olympic quest will likely be decided in the May Council meeting.
"You should conclude that these decisions will be taken at that point," the British two-time Olympic gold medallist said.
In Moscow, Russia sports minister Vitaly Mutko said he saw no "insurmountable obstacles" to Russian athletics being reinstated before the Olympics.
"I don't see any insurmountable obstacles that may prevent the closing of the issue in May," the R-Sport agency quoted Mutko as saying.
Mutko insisted Russia was doing everything possible to meet the strict criteria set by the world athletics ruling body but stressed that he believed the responsibility for doping code violation should be personal.
"When we speak about doping there're no guarantees possible," Mutko said. "It's all individual, that's why we're talking that there should be personal responsibility for doping use."
Russia was banned in November following a sensational report by an independent commission of the World Anti-Doping Agency (WADA) that found evidence of state-sponsored doping and large-scale corruption in Russian athletics.
The IAAF said Russia could only be reinstated if it fulfilled strict criteria outlined last year, including compliance with all WADA and IAAF anti-doping rules and requirements
The IAAF Council's decision was widely expected, coming just two days after influential anti-doping czar Dick Pound compared Russian efforts to combat doping in athletics to changing deckchairs on the Titanic.
Stripped of the right to international competition in November, Russia's athletics federation has been forced into a piecemeal reboot of its internal governance and anti-doping structures.
Pound's repeated doubts over Russian athletes competing in Rio follow another explosive documentary by German broadcaster ARD detailing continued violations by Russia's athletics programme.
Entitled "Doping Top Secret: Russia's Red Herrings", last week's ARD programme contained new allegations suggesting malpractice by several people in the Russian anti-doping system and alleges someone from the Russian Anti-Doping Agency (RUSADA) gave advance warning to athletes of testing plans.
"We're very concerned by the ARD programme," Andersen acknowledged, praising the Russian federation for changing the president and its council and introducing anti-doping education programmes, but questioning delayed verification process of athletes and coaches.