Russian athletes will remain suspended from international competition after their federation failed to meet anti-doping test deadlines.
The International Association of Athletics Federations (IAAF) has confirmed that the Russian federation has not met criteria to show meaningful drugs testing was being carried out in Russia.
Nineteen Russians will compete as neutrals at the World Athletics championships, which begin in London on Friday.
But most of their compatriots will be watching from home as the Russian federation remains suspended and atheletes are barred from competition.
The head of the IAAF Task Force rune Anderson said the main issue is that no meaningful drugs testing is being conducted in Russia.
"They have started but where they used to do 19,000 tests a year it's now just a few thousand and RUSADA (Russia's anti-doping agency) remains not code-compliant."
"Our impression is that they really want to meet all the criteria, they have shown huge progress since November 2015, but there are still issues to be resolved."
Andersen said he had noticed an encouraging change in culture "starting with the athletes" but added that there was still an issue with banned coaches continuing to operate freely, particularly in race walking, a discipline where Russia has had a terrible doping record in recent years.
The earliest possible return for Russia was November but in the light of the Task Force's concerns that looks extremely unlikely.
IAAF president Sebastian Coe said the world body's system of clearing individual Russian athletes to compete was working.
"We find the clean athletes and separate them from the tainted system," he said.