Over the past two decades US military personnel have reported seeing what are commonly referred to as UFO's - unidentified flying objects - but a new federal government report will say that there is no evidence these are alien spacecraft.
The newspaper said US intelligence officials believe experimental technology of a rival power could account for at least some of the aerial phenomena in question.
But senior USA officials cited in the Times article said the report's ambiguity meant the government was unable to definitively rule out theories that the unidentified phenomena might have been extraterrestrial in nature.
The report, the Washington Post said, "will offer no firm conclusions about what the objects. might be".
One possible explanation the report will put forward is that the UFOs are advanced technology from other countries, The Times reported.
But the review of more than 120 incidents over the past two decades was unable to explain the mysterious movements of the craft, which include unusual acceleration, direction changes and the ability to rapidly submerge.
While the report isn't expected to confirm the existence of extraterrestrial life, the mere fact that the intelligence community is set to acknowledge these incidents at all represents a remarkable shift in the way USA officials think about this phenomenon.
"There are a lot more sightings than have been made public", John Ratcliffe, who was director of national intelligence for the last eight months of Donald Trump's administration, said on Fox News in March.
But it then could not explain what, for example, US Navy pilots saw when they recorded objects travelling at seeming hypersonic speeds, spinning and mysteriously disappearing. The move is widely considered a U-turn by United States authorities, who have been reluctant to speak on the issue, let alone share information on UFOs.
News that the US Department of Defence will brief Congress on the information that it has about unidentified aerial phenomena has sparked intense debate among UFO enthusiasts.
Interest was piqued in the possibility of highly intelligent extraterrestrial life after the Pentagon released videos a year ago, in which Navy pilots express amazement at the fast-moving objects they see.
Former President Barack Obama has also confirmed there are UFO sightings that the government can not explain.
In 2017, David Fravor, one of the pilots recording the footage released in April 2020, described to the New York Times how one of the UFOs he saw "accelerated like nothing I've ever seen".
Former US Navy pilot Ryan Graves says the frequency of UFO sightings over restricted airspace is a security threat.
Graves told CBS he saw UFOs "every day for at least a couple years".