The incident occurred on September 10, when two US spy planes flying over the Strait of Hormuz were contacted by Iranian authorities and warned to change path or risk getting shot down.
The two planes, together carrying over 30 crewmembers, ignored the Iranian demand and continued on their path, which US officials said was strictly in international airspace though near Iranian territory.
“We wanted to test the Iranian reaction,” an official told Fox News about the incident. “It’s one thing to tell someone to get off your lawn, but we weren’t on their lawn.
“Anytime you threaten to shoot someone down, it’s not considered professional.”
Another unnamed source told the news channel US officials saw no danger in maintaining course as intelligence reports indicated there were no missile launchers in the area.
The region has seen a series of confrontations and provocations between the sides recently.
In late August Iranian ships harassed US naval vessels in the Persian Gulf in several incidents, including one that prompted an American ship to fire warning shots.
Video of once such incident involving the USS Nitze shows American sailors firing flares and sounding the warship’s horn as the Iranian boats approached. A sailor can be heard saying that the weapons on the Iranian boats were “uncovered, manned.”
A US defense official told AFP that ships from the US and Iranian navies had interacted more than 300 times in 2015 and more than 250 times the first half of this year.
Ten percent of those encounters were deemed unsafe and unprofessional, the official said.
AFP contributed to this report.