The Pentagon provided few details on the deployment. The announcement appears to indicate that the president has not made a decision about whether to take military action against Iran.
The Trump administration ordered new sanctions on Iran, in response to the attack in Saudi Arabia that temporarily cut off nearly 6% of the world's oil supply. The sanctions' effect may be limited.
"This attack did not originate from Yemen despite Iran's best efforts to appear so," said Saudi Col. Turki al-Malki. U.S. Secretary of State Mike Pompeo called it an "act of war" against the kingdom.
It's the largest one-day surge in crude prices in years. Yemen's Iranian-backed Houthi rebels claimed responsibility for the strikes, but the U.S. says Iran played a key role. Iran denies involvement.
Houthi rebels in Yemen have claimed responsibility for the attacks, but Secretary of State Mike Pompeo accused Iran of launching an "unprecedented attack on the world's energy supply."
In a break from tradition, the king appointed a prince to run the energy ministry and the head of the Public Investment Fund to chair oil giant Saudi Aramco.
A federal judge says the government must prioritize the release of documents requested under the Freedom of Information Act about the killing of Saudi journalist Jamal Khashoggi.