Iran has been accused by Ukraine’s president of selling more than 1,000 drones “and other weapons” to Russia.

Volodymyr Zelensky revealed the extent of Tehran’s sanctions-busting support for Putin's invasion of Ukraine in an interview with Italian media on Saturday.

Ukraine’s leader said: “Thanks to the sanctions, the number of missiles they [the Russians] produce has decreased several times. However, there are such challenges as Iran which has sold them [Russia] more than 1,000 Iranian-made drones and other weapons.”

Forces of the Russian Federation began using drones in its attacks against Ukraine's infrastructure last fall, temporarily depriving millions of Ukrainians of heating, water and electricity during the winter.

Iran first denied it had supplied drones to Russia but in early November foreign minister Hossein Amir-Abdollahian admitted the deliveries, while claiming they were sent before the Russian invasion.

Recent intelligence reports suggest that Tehran may be planning also to supply long-range missiles to Russia.

Ukraine says its air force has shot down more than 500 Iranian drones so far, figures confirmed by Western intelligence.

Iran’s supply of drones to Russia for use in its war on Ukraine has been condemned by the US and its NATO allies and met with sanctions by the US, European Union and other states.

Washington has halted talks with Tehran aimed at resurrecting a deal over Iran’s nuclear programme, indicating that it expects the Islamic Republic’s deliveries to Putin to stop before any further negotiations take place.