The first public congressional hearing into UFO sightings in the US in over 50 years ended with few answers about the unexplained phenomenon.
Two top military officials tasked with probing the sightings said that most can ultimately be identified.
But they said a number of events have defied all attempts at explanation.
The sightings recorded by the military include 11 "near-misses" with US aircraft.
Some Unexplained Aerial Phenomena (UAPs) - as the military terms UFOs - seem to have been moving without any discernible means of propulsion.
What happened at the hearing?
During the hearing at the House Intelligence Counterterrorism, Counterintelligence, and Counterproliferation Subcommittee, top Pentagon intelligence official Ronald Moultrie said that through "rigorous" analysis, most - but not all - UAPs can be identified.
"Any object we encounter can likely be isolated, characterised, identified and, if necessary, mitigated," Mr Moultrie said.
A small number of incidents, however, still have no explanation. In one such incident in 2004, fighter pilots operating from an aircraft carrier in the Pacific encountered an object that seemed to have descended tens of thousands of feet before stopping and hovering.
In another incident, shown publicly for the first time on Tuesday, an object can be seen on camera flying past a US Navy fighter jet. The object remains unexplained.
"There are a small handful [of events] in which there are flight characteristics or signature management that we can't explain with the data we have available," said Scott Bray, the deputy director of naval intelligence. "Those are obviously the ones that are of most interest to us."
Mr Bray also sought to dispel the notion that UAPs might be extraterrestrial aliens, noting that no organic or inorganic material or unexplainable wreckage has ever been recovered, and no attempts have been made at communicating with the objects.
"We have detected no eliminations within the UAP task force that...would suggest it's anything non-terrestrial in origin," he said.