US Secretary of State Mike Pompeo on Wednesday said the attacks on two oil refineries in Saudi Arabia were "an Iranian attack" that was an "act of war."

Pompeo told reporters off-camera on Wednesday that the attack on Saudi Aramco Facilities was directed by Iran, and that the claim of responsibility made by the Houthi rebels in Yemen "doesn't change the fingerprints of the Ayatollah as having put at risk the global energy supply."

"We were blessed that there were no Americans killed in this attack but any time you have an act of war of this nature, there’s always risk that that could happen,” Pompeo told reporters. “This is an attack of a scale we’ve just not seen before."

The Secretary of State also said that US intelligence officials are confident the Houthis who claimed responsibility for the attack do not have access to the weapons used as “these were not weapons that would have been in the possession of the Houthis.”

Pompeo called the Houthis liars and suggested that Iran might have influenced them to take responsibility. 

"This is important because you ought not report them as if these truth-tellers, as if these are people who aren’t completely under the boot of the Iranians and who would not, at the direction of the Iranians, lay claim to attacks that they did not engage in, which clearly was the case here," he said.

Over the weekend, Saudi Aramco had to close two of its facilities after they were hit by drones and then caught fire. The incident led to a cut in oil production totalling 5.7 million barrels per day — about half of Saudi Arabia’s daily oil output. The closure of oil facilities has triggered a surge in oil prices worldwide.

Two days later, US President Donald Trump said during a meeting with Bahrain’s Crown Prince Salman bin Hamad Al-Khalifa that based on evidence he'd seen, it appears as though Iran was responsible for the attack.