Saudi Arabia announced Monday that the weapons used in an attack on the nation's oil installations were Iranian in origin, further escalating tensions between Saudi Arabia, Iran, and the United States, according to The Washington Post.
The revelation comes after Secretary of State Mike Pompeo directly blamed Iran for the attacks Saturday. Neither the U.S. or Saudi Arabia has publicly presented the evidence of Iran's involvement yet. Iran has denied involvement in the attacks.
Meanwhile, Houthi rebels in Yemen, who have been supported by Iran, have claimed responsibility for the attack and threatened to strike again in the near future. Saudi and U.S. officials have said there is no evidence that the attack originated in Yemen.
Mohammed Albukhaiti, a Houthi spokesman, said they "don't need to provide evidence" that they are responsible for the attack, which disrupted 5 percent of the world's daily oil supply.
"We assure the Saudi regime that our long hand can reach wherever we want, and whenever we want," Houthi spokesman Yahya Saree said in a statement.
President Donald Trump did not outright blame Iran for the attack, but in a Monday tweet he cast doubt over Iran's truthfulness in such matters, referencing a recent dispute over a drone.
"Remember when Iran shot down a drone, saying knowingly that it was in their 'airspace' when, in fact, it was nowhere close," President Trump wrote. "They stuck strongly to that story knowing that it was a very big lie. Now they say that they had nothing to do with the attack on Saudi Arabia. We'll see?"
On Sunday, the president appeared to open the door to retaliation against Iran, pending verification from Saudi Arabia about the responsible party.
"Saudi Arabia oil supply was attacked," President Trump wrote on Twitter. "There is reason to believe that we know the culprit, are locked and loaded depending on verification, but are waiting to hear from the Kingdom as to who they believe was the cause of this attack, and under what terms we would proceed!"
European allies, as well as China and Russia, warned against being too quick to assign blame in this scenario before the evidence is conclusive.