The U.S. secretary of state said Iran was behind the missile strikes. Saudi officials said they had proof.
The president tweeted that he's authorized the release of strategic petroleum reserves "if needed" to stabilize energy markets after an attack on Saudi oil sites.
A fiery drone strike disrupted oil production at two giant Saudi facilities over the weekend. Secretary of State Mike Pompeo blames Iran.
Yemen's Houthi rebels have claimed responsibility for the attacks in Buqyaq and the Khurais oil field.