Russian officials visited an airfield in Iran to view attack-capable drones, US national security adviser Jake Sullivan said on Saturday.
Sullivan said earlier this week that the US has information showing Iran was preparing to provide Russia with up to several hundred drones, including drones that are weapons-capable.
However, Iran’s Foreign Minister Hossein Amir-Abdollahian has denied this.
The White House also released satellite imagery from June 8 and July 5 displaying images of Shahed 191 and Shahed 129 drones in flight at Kashan airfield, while a Russian delegation transport plane was on the ground.
The report comes while Moscow has declared it would be stepping up military operations in “all operational areas” in Ukraine.
The Ukrainian military said Russia appeared to be preparing for an offensive toward Sloviansk, a symbolically important city held by Ukraine in the easter region of Donetsk.
On Friday, Iran’s foreign minister, in a phone call with his Ukrainian counterpart Dmytro Kuleba, further rejected claims that Iranian drones were being sent to Russia for use in the war against Ukraine.