The missile missed the drone and fell into the water, the official said.
Prior to taking the fire, the American MQ-9 drone observed Iranian vessels closing in on the tankers, the official added, though the source did not say whether the unmanned aircraft saw the boats conducting an actual attack
Still, it is the first claim that the US has information of the Iranian movements before the attack
CNN has not seen any images from the US drones
Iran has strenuously denied any involvement in the attack. the official also said in the days before the attack, and the US reaper drone was shot down in the Red Sea by what is believed to be an Iranian missile fired by Houthi rebels.
The Pentagon had tough words for Iran on Friday as the US continues to assert its claim that Tehran was responsible for the attack on the two oil tankers in international waters after releasing video footage says Iranian patrol boat removing an unexploded mine "We are making sure that General McKenzie and the central command have the resources and support they need to conduct their missions," acting Defense Secretary Patrick Shanahan said, adding that US continues to work on building an international consensus that Iran was behind the attack.