The Ukrainian official said that Russia has stopped using Iranian-made drones because they don't work in winter.
According to Ukrainian news agency UNIAN, Yevgeny Silkin said that Russia had stopped using Iranian drones because they were made of plastic and not frost resistant.
The first day that it snowed in Ukraine this year was November 17th and the drones have not been used there since.
During the winter season in Ukraine, mean temperatures can be below freezing.
Russia began to use Iranian drones in October as part of a new strategy to target critical infrastructure from afar. The Ukrainians have been killed by drones.
Iran admitted that it had sent weapons to Russia before the start of the Russian invasion of Ukraine.
There are multiple reports and Western intelligence assessments that disagree with this.
The UK, US, and EU have imposed sanctions on the manufacturer of drones and others who supplied them to Russia.
CNN reported in November that Iran was about to give more weapons to Ukraine. It was reported that Iran and Russia had agreed to start making their own drones.
According to the UK's ministry of defense, Russia could purchase more drones.
Iran has been training Russia on how to use drones, according to multiple reports.
On December 3rd, the US National Intelligence Director said that winter conditions would slow the war and that there was already a reduced pace.