UN Secretary-General Antonio Guterres told the Security Council on Tuesday that the United Nations is "unable to independently corroborate" whether drones used in the September attack on Saudi oil facilities "are of Iranian origin", Trend reports citing Sputnik.
On 14 September, two combat drones attacked two major state-owned oil processing facilities run by Saudi Aramco in Abqaiq and Khurais, suspending the production of some 5.7 million barrels of oil per day.
Although the Houthi rebels have claimed responsibility for the strikes, Washington and Riyadh blamed them on Tehran.
Following the airstrikes, the US issued deploying additional forces and military equipment to Saudi Arabia to "help restore deterrence against Iranian aggression", as US Secretary of State Mike Pompeo wrote on his Twitter earlier in October.
The United States has repeatedly claimed that Tehran is pursuing "aggressive policies" destabilising the Middle East region. It has also called on other states to strengthen sanctions on Iran.