The Pentagon said it is investigating 171 unexplained UFO sightings in a report released just a month before four unidentified objects were shot down over North America.
The government's efforts to document the mysterious objects, known in official terms as “unidentified aerial phenomena”(UAPs), has led to hundreds of incidents being looked into, senior military leaders have said.
This comes as an object floating through US airspace was shot down on Sunday with officials refusing to rule out an alien origin.
On orders from President Joe Biden, a US fighter jet shot down an “unidentified object” over Lake Huron, near the border with Canada.
It was the fourth such downing in eight days and follows accusations from the US military against China of an extended surveillance operation.
Remains of the three latest objects shot down are being analysed, and their origin has not been determined yet, with an official refusing to rule out that this might be extra-terrestrial.
When asked on Sunday, General Glen VanHerck, who is in charge of North American Aerospace Defense Command and Northern Command, said: "I'll let the intel community and the counterintelligence community figure that out. I haven't ruled out anything.
"At this point, we continue to assess every threat or potential threat, unknown, that approaches North America with an attempt to identify it."
Despite the renewed interest and the numerous reports being investigated, so far no evidence of extraterrestrial life has been found.
Analysis of military sightings is conducted by the Office of the Director of National Intelligence (ODNI) along with a newly created Pentagon bureau known as AARO, short for the cryptically named All Domain Anomaly Resolution Office.
Their first report to Congress in June 2021 examined 144 sightings by US military aviators dating to 2004.
That study attributed one incident to a large, deflating balloon but found the rest were beyond the government’s ability to explain without further analysis.
A report from the ODNI issued last month cited 366 additional sightings, mostly things like balloons, drones, birds or airborne clutter.
But 171 remained officially unexplained.
“Some of these uncharacterised UAPs appear to have demonstrated unusual flight characteristics or performance capabilities, and require further analysis,” the office said in the report.
Ronald Moultrie, under secretary of defense for intelligence and security, told reporters in December that he had not seen anything in the files to indicate intelligent alien life.
“I have not seen anything in those holdings to date that would suggest that there has been an alien visitation, an alien crash or anything like that,” Mr Moultrie said.
