Russia's suspended athletics federation said on Thursday it had missed a July 1 deadline to pay millions of dollars to World Athletics, putting on hold the chances of its track and field athletes being able to compete internationally as neutrals.
World Athletics, the sport's global governing body, in March handed the federation a $10 million fine for breaching anti-doping rules.
World Athletics at the time reinstated the process by which Russian athletes could apply to compete internationally as neutrals after demonstrating that they train in a doping-free environment.
It said, however, that this process would again be suspended if half of the fine was not paid by July 1.
The Russian federation told TASS agency on Thursday that the fine had not been paid as of July 2, a day after the federation's president said it did not have sufficient funds to do so.
World Athletics later confirmed that the payment had yet to be made and that it had not been provided with "any information on when the monies may be paid, despite reminders and correspondence with the federation."
It said the federation had missed the deadline to pay $5 million of the fine and $1.31m in legal and other costs.
World Athletics said the Doping Review Board, which reviews Russians' applications to compete internationally, and the Russian Taskforce overseeing the federation's reinstatement efforts were standing down until the issue was discussed at a meeting of its Council later this month.
"We recognise these are difficult times, but we are very disappointed by the lack of progress made by RusAF (the Russian athletics federation) in terms of the requirements set in March," Sebastian Coe, president of World Athletics, said in a statement. "RusAF is letting its athletes down badly."
The federation was suspended in 2015 after a report commissioned by the World Anti-Doping Agency (WADA) found evidence of mass doping among track and field athletes in the country.