Iran is moving some drones and missile batteries as U.S. forces were placed on high alert Monday night, CNN reported.

U.S. forces and air-defense missile batteries in the Middle East were told to monitor for potential Iranian drones after intelligence suggested an attack on U.S. targets, two U.S. officials told CNN.

Intelligence saw Iran moving military equipment, including drones and missiles, over the last several days. U.S. officials told CNN the recent development could mean they are moving them in fear of a potential U.S. strike or they are preparing to conduct their own strike.

ADVERTISEMENT

An official told the news source that "there were indications that we needed to monitor the threats" more closely than at current levels. Another said the situation required "all Patriot batteries and forces in the area [to be] on high alert" against an "imminent attack threat."

The U.S. is preparing for strikes in Iraq, Kuwait, Saudi Arabia, the United Arab Emirates and Jordan based on intelligence, CNN reported, and the U.S. Maritime Administration has cautioned commercial ships in the Middle East about potential “Iranian action against U.S. maritime interests in the region.”

Iran has used missiles on its drones in other attacks, including a prominent strike at two Saudi oil refineries last year.

Tensions between the U.S. and Iran have intensified after a U.S. strike killed Iranian general, Qassem Soleimani, driving Iran to promise retaliation against America. U.S. officials have said the strike was conducted to avoid an “imminent” attack being planned by Soleimani but have declined to provide more details.

Trump threatened to strike 52 sites in Iran, including cultural sites, if the country retaliated, which Iran says violates international law.

Foreign Minister Mohammad Javad Zarif called the strike “an act of aggression” against Iran in an interview on CNN Tuesday.

“We will respond. But we will respond proportionally, not disproportionally," he said. "We will respond lawfully. We are not lawless people like President Trump Donald John TrumpBarr criticizes DOJ in speech declaring all agency power 'is invested in the attorney general' Military leaders asked about using heat ray on protesters outside White House: report Powell warns failure to reach COVID-19 deal could 'scar and damage' economy MORE."