A soon-to-be-released federal report into "unidentified aerial phenomena" didn't identify hundreds of mysterious objects spotted by military pilots but it concludes there isn't any evidence the objects were alien craft or U.S. military airplanes, The New York Times reports.

U.S. intelligence agencies will report to Congress a report later in June on its activities into recent sightings of unidentified objects in the sky.

The report concludes these objects aren't part of a secret U.S. military program, and it won't present any evidence to support fringe theories about aliens operating spacecraft near Earth's surface, according to unidentified sources quoted by the Times.

However, the Times report says the experts won't try to pass off the sightings as stray weather balloons or research instruments - the most common explanation offered by the government for unidentified objects.

The experts will tell politicians the origins of the sightings are unclear - though some experts say they could be advanced aircraft from U.S. adversaries like Russia or China.

"Unidentified flying objects were once associated with conspiracy cranks and sci-fi writers, but they've attracted the American public's fascination in recent years and some politicians and experts have called for more transparency on the topic," Forbes magazine reported Friday.

The Pentagon released several videos in April of fast-moving objects in the sky. The film was shot by military pilots. In May a Navy pilot told 60 Minutes he spotted similar objects off the East Coast "every day for at least a couple years." The military investigated some of these sightings via a previously undisclosed program between 2007 and 2012, and late last year, Congress asked intelligence agencies to produce a report by June.

"I want us to take (UFO sightings) seriously and have a process to take it seriously. I want us to have a process to analyze the data every time it comes in," Florida's Republican Sen. Marco Rubio told 60 Minutes. "Maybe it has a very simple answer. Maybe it doesn't."