An upcoming report by the Pentagon is expected to divulge that intelligence officials have not found any evidence that unexplained aerial phenomena witnessed by Navy personnel in recent years are alien spacecraft, according to a report by The New York Times .

The report also found the vast majority of incidents documented over the past two decades did not originate from any US military or other advanced government technology, the Times said, citing senior administration officials briefed on the report.

Many of the 120-plus sightings reviewed in the classified intelligence study from a Pentagon task force were reported by US Navy personnel, while some involved foreign militaries, the Times report said.

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.

One unnamed senior US official briefed on the report told the Times there was concern among American intelligence and military officials that China or Russia could be experimenting with hypersonic technology.

An unclassified version of the report expected to be submitted to Congress by June 25 will present few other conclusions, the newspaper said.

Public fascination with unidentified flying objects, or UFOs, was stoked in recent weeks by the forthcoming report, with UFO enthusiasts anticipating revelations about unexplained sightings many believe the government has for decades sought to discredit or cover up.

But senior US 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 National