The Pentagon on Friday released an initial group of previously secret files documenting reports of UFOs – a move sought for decades by some.

“These files, hidden behind classifications, have long fueled justified speculation – and it’s time the American people see it for themselves,” Pete Hegseth, the defense secretary, said in a statement posted on X.

The release follows a directive from Donald Trump in February for federal agencies to begin identifying, declassifying and releasing government files related to unidentified flying objects, now known as unidentified anomalous phenomena (UAPs), and the possibility of alien life beyond Earth.

The move, the US president said at the time, was “based on the tremendous interest shown” by the public, and reflected renewed appetite for information about the government’s knowledge of, and perceived involvement in, programs tracking and even housing supposed aliens and their spacecraft.

Last month Jared Isaacman, the new Nasa administrator, gave the drive for greater transparency at the agency more credence by stating the space agency planned missions to space at least in part because of the possible existence of extraterrestrial alien lifeforms.

“The odds that we will find something at some point to suggest that we are not alone are pretty high,” he told NBC’s Meet the Press.

Even so, the first batch of 162 files released on Friday, incorporating hundreds of pages on a monochrome new defense department website, offered little new or conclusive evidence.

The public, the Pentagon statement said, “can ultimately make up their own minds about the information contained in these files”.

They include old state department cables, FBI documents and transcripts from Nasa’s crewed flights into space, the Associated Press reported. Other pages, stretching back decades, feature ambiguous eyewitness accounts of encounters with, or alleged sightings of UFOs.

For example, one previously confidential 1947 report from Air Defense Command headquarters in New York features an account by the pilot and navigator of a Pan American World Airways (Pan Am) commercial jetliner who said they momentarily sighted a mystery “bright orange object” in the sky.

The object was visible for only seconds, then disappeared quickly behind a cloud and was not seen again, the crew members said.

A more recent document details an FBI interview with someone identified as a drone pilot who, in September 2023, reported seeing a “linear object” with a light bright enough to “see bands within the light” in the sky.

“The object was visible for five to 10 seconds and then the light went out and the object vanished,” according to the FBI interview.

Numerous other pages recount similar but unproven accounts of sudden, brief, or unexpected phenomena witnessed in the sky.

The Pentagon called Friday’s publication of the documents an “initial release”, in partnership with multiple federal entities including the White House, office of the director of national intelligence, energy department, the FBI and Nasa.

“Additional files will be released by the Department of War on a rolling basis,” the Pentagon said, using the unofficial name for the defense department.

“While all of the files have been reviewed for security purposes, many of the materials have not yet been analyzed for resolution of any anomalies,” it conceded.

Despite Friday’s hyped release, the policy of the defense department “drip feeding” information to the public is not new.

In 2024, a Pentagon report concluded there was no evidence of extraterrestrial activity, and that most sightings were weather related or misidentified balloons, birds or satellites.

Earlier the same year, a separate report published by the All-Domain Anomaly Resolution Office said the government was not, and never had been secretly hiding alien technology or extraterrestrial beings from the public, and that a rumored facility in the New Mexico desert purportedly housing alien beings and spacecraft was a hoax.

It followed a claim by former US intelligence official and whistleblower David Grusch that the US government conducted a “multi-decade” secret UFO program that found “non-human” beings.