JEDDAH, Saudi Arabia (Reuters) - Saudi Arabia will restore its lost oil production by the end of September and has managed to recover supplies to customers to the levels they were at prior to weekend attacks on its facilities by drawing from its huge oil inventories.

Energy Minister Prince Abdulaziz bin Salman said on Tuesday that average oil production in September and October would be 9.89 million barrels per day and that the world’s top oil exporter would ensure full oil supply commitments to its customers this month.

“Over the past two days we have contained the damage and restored more than half of the production that was down as a result of the terrorist attack,” Prince Abdulaziz told a news conference in the Red Sea city of Jeddah.

He said the kingdom would achieve 11 million bpd capacity by end of September and 12 million bpd by end of November.

“Oil supplies will be returned to the market as they were before 3:43 a.m. Saturday,” he said, adding that state oil giant Aramco had emerged “like a phoenix from the ashes” after the attack.

He was referring to attacks on Saturday on state-owned oil company Saudi Aramco’s plants in Abqaiq and Khurais, including the world’s largest oil processing facility, which shut down 5.7 million barrels per day, which is more than half of Saudi Arabia’s production, or 5% of global output.

Aramco’s Chief Executive Amin Nasser said the company, which is preparing for an initial public offering (IPO), was still in the process of estimating repair work but that it was “not that significant,” given the company’s size.

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“We should be at our production (level) before the attacks on our facility by the end of September,” Nasser told the same news conference.

Aramco had put out 10 fires in the span of seven hours after the “huge” assault, Nasser said.

He said the company was in the process of bringing back oil refining to full capacity and that there were enough crude products to supply the local markets. Aramco’s crude oil inventories are more than 60 million barrels, he said.

Speaking at the same news conference, Aramco’s Chairman Yasser al-Rumayyan, said Aramco’s IPO would be ready within the coming 12 months and that the kingdom was committed to the listing.

Rumayyan said the IPO would “continue as it is” despite weekend attacks and that timing would depend on market conditions.

Prince Abdulaziz said Riyadh did not yet know who carried out the strikes or why, adding Saudi Arabia would keep its role as a secure supplier of global markets. He said stricter measures needed to be taken to prevent further attacks, but did not elaborate.

The foreign ministry has said that preliminary investigations indicated Iranian weapons were used in the assault, which authorities initially said involved drones.