Two Iranian fighter jets fired on an unarmed US drone in the Gulf last week and missed, the Pentagon has said, warning that the US stood ready to protect its forces in the region.
The incident occurred on November 1, less than a week before the US presidential election, the Department of Defence said.
“They intercepted the aircraft and fired multiple rounds,” spokesman George Little told a news conference on Thursday.
The exchange is the latest episode between the two countries amid a mounting crisis over Tehran’s nuclear programme and a shadow war marked by cyber-attacks and assassinations in Iran.
Tough new sanctions led by the US are squeezing Iran’s economy while Washington is accused of staging cyber sabotage on Tehran’s uranium enrichment plants.
The United States and other Western powers have charged that Iran’s nuclear program is aimed at developing nuclear weapons, but Tehran insists the program is for peaceful purposes.