The U.S. Navy keeps unpublished footage of unidentified flying objects (UFOs, but will not release the footage because it would harm national security, a Navy spokesman wrote, Live Science writes.

The admission was made in response to a Freedom of Information Request (FOIA) filed by The Black Vault website, which previously posted thousands of pages of UFO-related documents obtained through FOIA requests to the CIA and other government agencies. The Black Vault filed the request with the U.S. Navy in April 2020 - just one day after the Navy declassified three now-famous videos taken by Navy pilots showing high-tech flying machines moving in seemingly impossible ways. Black Vault demanded that the Navy turn over all other UAP-related videos.

More than two years later, the government responded with a letter confirming that other UAP videos existed and denied the request to turn them over on national security grounds.

The U.S. military takes the potential threat of UFOs very seriously. In May 2022, the Defense Department held the first public hearing on UFOs since the 1960s. The hearing mainly discussed a June 2021 Pentagon report, which reported that U.S. Navy pilots had reported 144 UFO sightings since 2004. More recently, the Defense Department announced that it would receive federal funding to open a new office to handle exclusively UFO sighting reports from the U.S. Army, Navy and Air Force.