"UAV used by the Russian army in Ukraine are manufactured in Russia," Polyanskiy said on Wednesday, adding that Western officials are inventing artificial pretext.
The official further added that the United Nations Secretariat does not have a legal mandate to conduct an investigation into the alleged use of Iranian-made drones in Ukraine.
"[The UN Secretariat] has no mandates to investigate anything regarding the UN Security Council resolution 2231," Polyanskiy said. "Its role as enshrined within note of the Security Council President 2016/44 16 January 2016 is purely technical - to prepare meeting rooms, circulated communications."
The comments come after the EU spokesperson Nabila Massrali revealed that the block had collected evidence allegedly proving that Iran had supplied Moscow with drones for its ongoing special military operation.
Iran has repeatedly rejected the accusations. Earlier, Iranian UN envoy Saeed Iravani blasted the "disappointing" claims as disinformation being pushed as part of a political agenda.
"We categorically reject the unfounded and unsubstantiated claims that Iran has transferred UAVs for the use in the conflict in Ukraine," Iravani said on Wednesday.
Allegations regarding the drones first surfaced in July, when they were voiced by US national security adviser Jake Sullivan. The US State Department has since stated that it intends to use sanctions to prevent the transfer of such "dangerous weapons."