By Dmitry Solovyov

MOSCOW (Reuters) - Russia on Thursday called into question the veracity of a new report by the World Anti-Doping Agency (WADA) which accused Russian athletes of still doping, but it promised to facilitate the agency's work.

Russia is bracing itself for a decision by the International Association of Athletics Federations (IAAF) on Friday which could determine whether its athletes can take part in the Rio Olympics in August.

In its report, WADA concluded that Russian athletes continued to fail drug tests and obstruct doping control officers.

It was the latest in a long line of setbacks for Russia's sporting image which have infuriated the Kremlin and drawn allegations from some officials of a deliberate Western smear campaign against Russia.

"I do not know what these assertions are based on. They need to be thoroughly analyzed by our sport experts," Kremlin spokesman Dmitry Peskov told a conference call with reporters on Thursday.

"It's not clear what WADA is basing all this on. There have been allegations (in the past) where WADA has based its results on concrete tests," he said. "But what are these (latest) allegations based on?"

The IAAF suspended Russia last year over concerns its athletes were guilty of systematic doping. On Friday, it will rule whether Moscow has done enough since then to have the ban reversed.

Peskov declined to say if the Kremlin would consider legal action if the IAAF ruled against Russia, a course of action Russian Sports Minister Vitaly Mutko has not ruled out.

Reacting to WADA's damning report, Mutko said on Thursday the authorities were ready to assist the agency in testing Russian sports people for doping any way it could and in any part of Russia.

WADA had complained that testers were routinely obstructed from gaining access to special closed military cities in Russia where athletes sometimes train.

Drug testers were reportedly intimidated when accessing military cities by armed agents threatening them with expulsion from the country, it said, and once allowed to enter, security staff created significant delays for them.

"I tell you once again: If you need any assistance from the government, just say so. We will do anything we can for (WADA) officers to be able to visit any city, even the ones with limited access," Interfax news agency quoted Mutko as saying.

(Additional reporting by Vladimir Soldatkin, Polina Devitt and Jack Stubbs, Editing by Andrew Osborn and Angus MacSwan)