Several U.S. cabinet officials, including Secretary of State Mike Pompeo and U.S. Secretary of Energy Rick Perry, have blamed Tehran for the attacks, which cut 5% of world crude oil production.

Iran has denied blame, with Iranian President Hassan Rouhani saying the strike was carried out by “Yemeni people” retaliating to attacks by the Saudi-led coalition in Yemen’s four-year-old war.

Trump said the United States had a lot of options to respond to the attacks, but declined to say what measures he was considering. He added that, while the United States could help, he had not promised protection to Riyadh.

The attacks on Saudi Arabia have damaged the globe’s largest crude processing plant and triggered the biggest jump in oil prices in nearly 30 years. (Reporting by Steve Holland; Writing by Makini Brice Editing by Marguerita Choy)