Russian forces are continuing their attacks on Ukraine using Iranian-made unmanned aerial vehicles, or UAVs, as Russia and Iran step up military cooperation.

Ukraine's Air Force said on Thursday that Russia fired 33 Iranian strike UAVs and Ukrainian forces destroyed 22 of them. The Air Force also said Russia conducted a missile attack in the eastern region of Kharkiv.

Ukraine's minister for strategic industries, Oleksandr Kamyshin, said on Wednesday that the country used the air defense system of the FrankenSAM project for the first time in combat conditions and shot down an Iranian drone.

The air defense system combines advanced surface-to-air missiles with Soviet-era weaponry still in Ukrainian stockpiles.

Ukraine's desperate efforts to secure more air defenses have led to the project as the country struggles with shortages of weapons and funds.

Russia's foreign ministry spokesperson Maria Zakharova told reporters on Wednesday that Russia and Iran are in the final stages of approving a new treaty.

She said the international context has changed and relations between the two countries are experiencing an unprecedented upswing.

She added that the new treaty would consolidate the strategic partnership between Moscow and Tehran, and cover the full range of their ties.

Last month, Russian President Vladimir Putin invited his Iranian counterpart Ebrahim Raisi to Moscow and held a summit meeting.

Top foreign and defense officials from Russia and Iran held phone talks on Monday and reaffirmed close ties between their nations.

Russia is said to seek ballistic missiles from Iran, while Iran is trying to purchase fighter planes from Russia.

Western nations and Iran's rivals in the Middle East are boosting vigilance against military cooperation between Russia and Iran.