The Russian Federation has offered scientific know-how to the Iranian military industry, but Iran still refuses to support the Russian Federation in the supply of ballistic missiles, head of the Main Intelligence Agency Kyrylo Budanov has said.

"Iran is not hurrying to do this, for understandable reasons, because as soon as Russia fires the first missiles the sanctions pressure will grow," Budanov said in an interview with The New Your Times published on Saturday.

According to him, under a contract reached over the summer, Russia acquired 1,700 so-called Shahed exploding drones from Iran. They are delivered in tranches. So far, Russia has fired about 540 of the drones in tactical strikes along the front line and in barrages aimed at power plants, pylons for transmission lines and electrical substations. Most of the small, delta-wing flying bombs are shot down before reaching their targets, the head of the Main Intelligence Agency said.

In Iran, Budanov said, the manufacturing cost is about $7,000 per unit, though it is unclear how much Iran actually charged Russia for the weapons.