There is no evidence of aliens or extraterrestrial intelligence, a Pentagon report that examined the sighting of Unidentified Flying Objects (UFOs) over the last century said on Friday.

The report concluded that most of the sightings reported were misidentified ordinary objects and phenomena, a conclusion that matches the assessment of past US governments into the claims.

The report from the Defense Department's All-domain Anomaly Resolution Office (ARRO) analyzed US government investigations since 1945 of UFO sightings.

The study which followed a 2022 Pentagon announcement also said that there were no efforts by the US government or private firms to keep the information about them secret.

"All investigative efforts, at all levels of classification, concluded that most sightings were ordinary objects and phenomena and the result of misidentification," said the report, which was mandated by Congress.

Why was the investigation conducted?

Over the past several years, US authorities have received a slew of reports of UFO sightings.

In 2021, a government report that examined 144 sightings held that no evidence of any extraterrestrial life was found and it called for better data collection.

The issue was once again brought to the fore last year after a retired Air Force intelligence officer testified to Congress that the US government hides a longstanding plan that reverse engineers unidentified flying objects.

The authors of the report said they wanted to meticulously investigate the subject which has occupied many American minds over the years.

"AARO recognizes that many people sincerely hold versions of these beliefs which are based on their perception of past experiences, the experiences of others whom they trust, or media and online outlets they believe to be sources of credible and verifiable information," the report said.

Another volume of the report will be published later.

mfi/rc (dpa, AP, Reuters)