The US government was unable to explain 143 of the 144 unidentified flying object sightings reported by military aircraft, according to a widely anticipated intelligence report released on Friday.

The aim of this report, issued by the Office of the Director of National Intelligence, was to shed light on the mystery of dozens of flying objects, which were observed between 2004 and 2021, but he said he did not find enough data to explain those incidents, with the exception of one related to an empty balloon.

The report, which was requested by the US Congress, added that “the rest is still unexplained.”

The report explicitly stated that “unusual” activity had been reported on multiple occasions, but did not rule out that these incidents were the result of errors.

The report said that a limited number of accidents, it indicated that “unspecified weather phenomena showed unusual flight characteristics”, and that the observations may be “the result of errors in the sensors.”

The report does not mention extraterrestrials, and does not even hint at any alien explanation for the reported sightings, but it does make clear that many phenomena may be beyond the capacity of the current means available to the government to identify these things.

According to the report, 18 incidents were reported in which some type of “unusual motion or flight characteristics”, including propulsion or other technology, were reported.

The report noted that all incident videos released so far have not been explained, and added that the limited amount of anecdotal data, i.e. non-scientific, in addition to the inconsistency in reporting due to the lack of a standardized system, makes the assessment of UFOs a challenge.

A senior US government official said, before the report was released, Friday: “We have no clear indications of any extraterrestrial explanation for it (those phenomena), but we will go wherever the data takes us.”

The official added that no data indicated that any of these unspecified weather phenomena were part of a foreign program, or “indicate significant technological advances by a potential adversary.”

Last month, officials spoke of the upcoming report, telling NBC News that the government had not ruled out the possibility that the flying objects seen by US military aircraft were highly advanced aircraft, made by other countries.

Those officials also said the objects did not appear to be evidence of secret US technology, but they did not categorically rule that out either.

But the report said these “unspecified weather phenomena” present aviation safety issues and potential operational security issues.

The US Department of Defense established the Unidentified Weather Phenomena Task Force last August to investigate and “gain insight” into the “nature and origins” of unidentified flying objects.

Earlier last year, the Defense Department declassified three videos taken by Navy pilots, one from 2004 and two from 2015, that showed UFOs flying at high speeds in the sky.

US lawmakers last year sought to erase the stigma attached to a serious discussion of UFOs, passing legislation requiring the Pentagon and the intelligence community to provide more information about UFO sightings, which until recently remained shrouded in secrecy.