Saudi Arabia accused Iran of conducting the weekend attack on the world’s largest oil processing facility, saying Wednesday there is no question Tehran was responsible.

Saudi defense ministry spokesman Turki al-Maliki said the attack Saturday on the Aramco facility at Abqaiq and nearby oil fields was “unquestionably sponsored by Iran.” The attack wiped out half of Saudi Arabia’s production capacity – about 5% of the world’s daily output. Officials said half that was restored byTuesday, and the facility is expected to be at full capacity by the end of the month.Iran-backed Houthi rebels in Yemen had claimed responsibility for the attack, but that was not the case “despite Iran’s effort to make it appear so,” al-Maliki said.

He added: “We have witnessed distinct growth in Iranian aggression. This attack wasn’t against Saudi Aramco or Saudi Arabia, it was against the international community.”

Investigators have been collecting debris from the attack site, including parts of drones and missiles that had been made in Iran. A recovered circuit board was expected to supply some insight on the weapons’ path. Satellite pictures and radar images indicate the weapons came from the north, either originating in Iran or a vessel in the Persian Gulf.

Iran has denied any role in the attack, which came as President Trump flirted with the possibility of face-to-face talks with his Iranian counterpart on the sidelines of the U.N. General Assembly meeting next week in New York. He has since cooled to the idea.

Iranian Supreme Leader Ali Khamenei ruled out any talks with the U.S., and media reports Wednesday indicated President Hassan Rouhani and other officials might skip the meeting altogether. Khamenei has made any talks conditional on the U.S. rejoining the nuclear deal from which Trump pulled out nearly a year-and-a-half ago.

Trump tweeted Wednesday he had asked Treasury Secretary Steven Mnuchin to crank up sanctions against Iran.

U.S. Secretary of State Mike Pompeo traveled to Jeddah to consult with Saudi leaders. Shortly before landing he told reporters Iran was responsible for the attack, which he characterized as "an act of war."

Though Saudi Arabia has spent billions on U.S. weapons, its batteries of Patriot missiles were pointed south toward Yemen from where past attacks have emanated. U.S.-operated batteries in the middle of the country were too far away to be of any help when two dozen drones and a complement of missiles flew in from the north.

NPR reported U.S. satellites detected activity around Iranian launch sites before the attack, providing circumstantial evidence of Iran’s culpability.

Saudi Arabia and Iran have been fighting a proxy war in Yemen since 2015, and experts said the weekend attack threatens a wider regional conflict.