The Pentagon has declassified three videos of "unidentified aerial phenomena" which show strange objects racing across the sky.

The black and white videos were recorded by Navy pilots - one in November 2004 and two in January 2015, the US Department of Defense said.

The footage had been shared online unofficially and was well known to UFO enthusiasts but the Pentagon said on Monday that it had chosen to release the videos officially.

One of the clips shows a dark circular object flying in front of a jet, another shows a small object speeding over land and the third shows a circular object racing and then appearing to slow down as it approaches the camera.

One of the videos was filmed over the Pacific and the other two were on the US east coast, according to reports.

In one of the 2015 videos, a voice can be heard saying: "There's a whole fleet of them."

Another voice adds: "They're all going against the wind. The wind's 120 knots to the west. Look at that thing, dude!"

Nick Pope, who previously investigated UFOs for the Ministry of Defence, told Sky News he did not have a "definitive explanation" of what was captured in the footage but it could be something "extra-terrestrial".

He said: "Assuming we're not dealing with a combination of pilot misperception and forward-looking infrared camera anomalies, (which is unlikely, as a lot of this was captured on radar too), there are very few options.

"US black project technology being blind-tested against the military as part of the evaluation process, a Russian or Chinese drone engaged in reconnaissance, or something genuinely unknown and yes, perhaps even extra-terrestrial."

Mr Pope added as the Pentagon has refused to confirm or deny what the shapes are, there could be "further revelations ahead".

"The Department of Defense doesn't seem to have ruled out this option," he said. "This is a hugely significant move. While these videos have been in the public domain for a while, this official Pentagon acknowledgement is big news.

"The timing is interesting too and will no doubt start a few conspiracy theories, as this has been done while the world is focused on coronavirus stories.

"I'm aware that the president and various senators have received classified briefings on these videos and on other US navy UFO sightings, and while even they may have been told that these videos remain unidentified, I know from my own government work that the military intelligence community will have a best current assessment, which was presumably shared with President Trump and others."

The US Department of Defense said in a statement: "DOD is releasing the videos in order to clear up any misconceptions by the public on whether or not the footage that has been circulating was real, or whether or not there is more to the videos."

They added that the videos had been reviewed to determine that they did not reveal any "sensitive capabilities or systems" or "impinge on any subsequent investigations of military air space incursions by unidentified aerial phenomena".

The Pentagon has released 3 previously-leaked videos of 'unidentified aerial phenomena'' aka UFOs! Download the RADIO.COM App today and stream your favorite ...