The first two batches were made public on May 8 and May 22.
President Donald Trump is the latest president to release US government reports on unidentified flying objects, a disclosure process that began in the late 1970s.
Friday's release of what the Pentagon calls "unidentified anomalous phenomena" (UAP) involved 72 files from the FBI, CIA and Pentagon and includes testimony, videos and artistic depictions.
Reports from several entries refer to sphere or orb sightings in the same general northeast US location.
One file from February 2026 cites FBI interviews with two people who reported seeing an intense bright light in the middle of their backyard one evening.
The identities of those interviewed and their precise location were blacked out.
One person "described the red colour as being brilliant and beautiful, and that (redacted) had never seen anything that colour of red before," according to the FBI report.
The red sphere, about one metre wide, contained a "white plasma sun" the size of a basketball in its centre, it said.
The people noticed a second orb and the two appeared tethered together as they moved away.
They reported seeing several white orbs a few weeks later flying over the house at a much higher altitude, the FBI report said.
A similar interview in July 2025 referred to previous reports of orbs.
"This observation occurred within 25 miles of the 'Triangle Orbs,' 'Red Orb Rotation,' and 'Orbs Over the Pond,' sightings at a location well known to them, which is sparsely populated," the FBI report said.
An October 2024 incident describes a light source below the horizon, hovering above a pond.
"The luminous object resembled a 'plasma-like sphere' intermittently changing shape and luminosity. At times, the primary light source appeared to separate into smaller luminous points," according to the report.
Another case highlighted in the files occurred in February 2022 in Colorado Springs, Colorado.
Five US army members at Fort Carson walked out of an office building and saw something strange hovering over Cheyenne Mountain, a few miles to the west.
"The object was 'potato' shaped with distinct edges and appeared to look painted in a creamy/whitish opalescent colour," according to an account in an FBI document.
It was made up of "articulating fish scales or panels that were non-symmetrical, non-overlapping and irregular shaped".
It stayed motionless, shimmering, for about two minutes, the men recounted to the FBI.
Then it vanished in the blink of an eye.
None of the men had phones on them and there is no video or photos of the incident.
Authorities tasked with investigating the episode said they could not explain it easily.
Their report concluded - with "low confidence" - that it may have been "backscattering of sunlight".
Low light from the rising sun could have reflected off the mountain's snow and illuminated low clouds above, it said.
The four-page report, heavily redacted and attributed only to an "intelligence community partner," said it did not appear to be technology from a foreign adversary.
"These files, hidden behind classifications, have long fuelled speculation - and it's time the American people see it for themselves," Pentagon chief Pete Hegseth said in a statement.
with AP
