translated from Spanish: US says there is no evidence of UFOs but there are unexplained phenomena

An official U.S. report concluded that there is no evidence that Unidentified Flying Objects (UFOs) exist but acknowledged that it is difficult to explain some mysterious phenomena observed by military pilots. In the brief, reported by The New York Times and other media, the Military and intelligence found no evidence that UFOs sighted by military pilots were extraterrestrial spacecraft. However, the report does not explain dozens of phenomena and incidents, some filmed by the pilots, so the existence of aliens cannot be absolutely ruled out.
Nor does it explain, for example, what U.S. Navy pilots saw when they filmed objects traveling at near hypersonic speeds, mysteriously spinning and disappearing. The investigation was requested last year and the result will be forwarded to Congress later this month by the director of national intelligence. The main report may be made public but shall have annexes which shall be kept secret. Interest in the possibility of highly intelligent extraterrestrial life deepened after the Pentagon released videos in which pilots expressed their astonishment at rapidly moving unknown objects.
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Original source in Spanish