A senior U.S. Northern Command (NORTHCOM) official told members of the Senate that some of the 350 drones that flew over military installations and sensitive areas last year may have been conducting surveillance.
U.S. Air Force Gen. Gregory Guillot, who is commander of NORTHCOM and North American Aerospace Defense Command (NORAD), was questioned about the drones during a Senate Armed Services Committee Budget hearing on Thursday.
Drones were spotted flying all over the country last year, though most notably in New Jersey. They were also flying over military installations, including Joint Base Langley, Wright-Patterson Air Force Base and Vandenberg Space Force Base.
Sen. Tom Cotton, R-Ark., asked Guillot about the threat the unmanned aircraft pose to military operations, facilities and personnel.
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"Senator, the primary threat I see for them in the way they've been operating is detection and perhaps surveillance of sensitive capabilities on our installations," Guillot said. "There were 350 detections reported last year on military installations, and that was 350 over a total of 100 different installations of all types and levels of security."
He confirmed that base commanders at sensitive sites like nuclear bases have the authority to protect their airspace from drone incursions, adding that those particular military sites account for about half of what the U.S. operates.
Cotton was flabbergasted that only about half of the bases have the ability to protect themselves from drones.
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He said base commanders at every base in the U.S. have the ability to protect their ground if a terrorist drove a dump truck though the front gate of a military facility, which Guillot agreed.
Cotton also raised concerns that at the southern border last week, Mexican cartels were reportedly authorized to use drones equipped with explosives against U.S. Border Patrol agents.
He asked Guillot if the Department of Defense needed authorization to share information with the Department of Homeland Security and other border patrol agencies about drone incursions and was told that was the case.
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Guillot advocated for an expansion of military capabilities when it comes to drones, especially when it comes to protecting bases and being able to exchange data with other government agencies about drones, seamlessly.
White House press secretary Karoline Leavitt told reporters late last month that the drones seen flying over New Jersey in large numbers recently were "authorized by the FAA for research and various other reasons."
In addition to those authorized by the FAA, other drones flown by hobbyists were sighted, and that number increased as curiosity about the phenomenon grew, the White House said.
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"This was not the enemy," Leavitt said.
The drone sightings in November and December originally raised public concerns and even attracted the attention of the FBI.
"The FBI Newark, NJ State Police, and NJ Office of Homeland Security and Preparedness are asking for the public to report any information related to the recent sightings of possible drones flying in several areas along the Raritan River," a Dec. 3 FBI statement noted.
The Federal Aviation Administration even issued temporary flight restrictions after the large number of sightings, prohibiting drone flights over parts of New Jersey.
Fox News Digital’s Chris Pandolfo contributed to this report.