The Pentagon already had begun taking measures to strengthen its firepower in the Middle East and protect U.S. bases there.

Iran has attacked a U.S. base in Qatar, calling the mission "Annunciation of Victory," according to Iranian state TV. The attack is focused on Al Udeid Air Base, according to the Islamic Revolutionary Guard Corps.

Iran retaliated against the U.S. on Monday, launching missiles at a U.S. base in Qatar, according to a statement from the Qatar foreign ministry. The missiles targeted Al-Ubaid Air Base outside Doha and were intercepted by air defenses before they could strike the base, the Qatari government said.