The White House said that Russian officials have visited Iran at least twice to look at drones.
Satellite images show Russian officials in Iran in June and July, according to the AP.
As President Joe Biden visits the middle east, he promised not to walk away from the region and that it would be filled by China, Russia or Iran.
The development shows that Russia is making a bet on Iran, according to a senior US official.
Jake Sullivan, the National Security Adviser, told reporters last week that Iran was going to give Russia up to hundreds of unmanned aerial vehicles, including weapons- capable drones.
Iran is preparing to train Russian forces to use these drones, with the first training session scheduled for July. It's not clear if Iran has delivered any of the drones to Russia yet.