A highly anticipated UFO report prepared by the U.S. intelligence community is expected to be presented to congressional committees on Friday, according to a U.S. official, but officials have told ABC News the report will not provide definitive explanations for the dozens of encounters reported by the U.S. military with unidentified aerial phenomena, or UAPs.

       And in a development certain to disappoint UFO enthusiasts who have hoped that the report may have found links to alien spacecraft, the report has not found any evidence to suggest any links to such theories, according to three officials.

       The report prepared by the Director of National Intelligence (DNI) was required by the Intelligence Authorization Act passed by Congress late last year. The U.S. intelligence community was given 180 days to prepare an unclassified and classified report on what the U.S. government knew about UAP's.

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       U.S. Dept. of Defense via AFP via Getty Images, FILE

       This video grab image obtained April 28, 2020, courtesy of the U.S. Department of Defense shows part of an unclassified video taken by Navy pilots that have circulated for years showing interactions with "unidentified aerial phenomena".

       The report, a according to a U.S. official, can be expected to outline some possible scenarios that might or could indicate possible explanations for UAPs.

       It remains unclear if the unclassified version of the report will be made public, but due to classification requirements the classified version will not be made public.

       To the Stars Academy of Arts and Science

       Video footage released by the To the Stars Academy of Arts and Science purportedly shows pilots observing a UFO while aboard a U.S. Navy aircraft.

       The review of dozens of UAP incidents reported by U.S. military personnel in recent years did not find any evidence to suggest they are linked to alien spacecraft, nor are they in a position to explain what has been reported by U.S. military pilots in encounters over the years, three U.S. officials said.

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       One of the officials told ABC News that some of the dozens of incidents involving UAPs were able to be explained, for example as weather balloons or as atmospheric conditions, but many other incidents could not be explained.

       A fourth official said that investigators have also ruled out the possibility that UAPs are related to any secret U.S. military technology, or so-called "black programs."

       The Pentagon has consistently referred questions about the upcoming report to the DNI, noting that office was preparing the report, choosing not to comment on a report not yet completed.