Pentagon commander says number of drones in US airspace at Mexico border 'alarming'

U.S. Border Patrol estimates over 1,000 incursions a month

A senior Pentagon official estimate the number of drones entering U.S. airspace without authorization at the U.S.-Mexico border is roughly 1,000 a month – a figure he calls "alarming."

"The number of incursions was something that was alarming to me as I took command last month," Air Force Gen. Gregory M. Guillot said Thursday when asked at a Senate hearing about the matter. 

However, he did not know the exact numbers of airspace intrusions – known as "incursions" – but said border patrol agents confirmed that the number was in the thousands. 

"I don't know the actual number," he said. "I don't think anybody does, but it's in the thousands. I would say in probably over a month we could probably have over 1,000 a month."

Guillot has served as commander of U.S. Northern Command and North American Aerospace Defense Command since February. 

U.S. Customs and Border Protection officials have said previously that cartels from Mexico have used drones to track the location of authorities in order to smuggle people and drugs into the U.S., according to the New York Post.