AN American pilot who claims to have chased an alien aircraft has warned world leaders to take UFO sightings seriously.

Retired US Navy pilot commander David Fravor spoke out in support of ex US government intelligence officer Luis Elizondo, who last week revealed he ran a real life "X Files" UFO research department at the Pentagon named the Advanced Aviation Threat Identification Program (AATIP) funded by £16 million ($22m) “black ops money” from Congress.

8 The strange object can be seen hovering in the fighter jet's sights Credit: YouTube Secureteam10

Elizondo secured the release of previously classified US Defense Department videos of UFO encounters - one of which shows the craft Fravor saw darting off at an incredible speed.

Commander Fravor, 53, was flying one of two fighter jets on a routine training mission about 100 miles into the Pacific ocean off San Diego when they were diverted to check out an aircraft spotted on radar from their navy cruiser the USS Princeton.

The operations operator said they had been tracking up to a dozen mystery aircraft over two weeks but hadn't had manned planes deployed when they showed up.

The object first appeared at 80,000ft, then hurtled towards the sea, stopping at 20,000 feet and hovering before dropping out of radar.

8 It then rapidly shoots off to the left out of sight Credit: YouTube Secureteam10

When Commander Fravor arrived he saw a white aircraft hovering 50 feet above above a disturbance in the ocean.

He said: “It was just moving randomly around - this 40 foot long white tic tac looking thing, with no wings.

“It was a clear day with a blue background and it was perfectly white. We didn't see any windows, no form of propulsion, nothing, just a big white object.

"It was rounded on both ends and had a cylindrical body which rounded in, same front to back.

“I couldn't tell what it was made of, it was bright white but it wasn't reflecting a bunch of light."

Fravor flew towards it and the aircraft began ascending towards him, passing him at about 12,000 ft. He thinks he got within half a mile of it.

8 Another remarkable video shows an object in the sights of a US fighter jet near San Diego Credit: US Department of Defense

He said: “I literally chased the thing and it started to mirror us, it was like it became aware we were there. I cut across to see if I could get closer and it rapidly accelerated and disappeared. Within a matter of a second it was gone.”

Asked what was going through his mind, he said: "I was thinking 'That's pretty strange'. In 16 years of flying I had never seen anything like that. Nothing that can hover and climb at that rate up and then accelerate and just disappear.

“I was more curious then afraid. I wanted to see how close I could get to it, to see what it was.”

The two fighter jets were told to head to a rendezvous point 60 miles away.

8 It was filmed travelling over the sea near San Diego in 2004 Credit: US Department of Defense

However the radio operator on the Princeton then radioed and said the mystery aircraft had turned up before them.

At this point another aircraft was sent to investigate and recorded radar footage of the aircraft. The 90 second video shows the oblong shaped object hovering before it darts off to the left at what appears to be an unprecedented velocity.

Fravor said: “It jammed the radar, you couldn't lock it with a conventional radar, you could passively track it and see it, but if you tried to grab a lock it wouldn't allow you to do that.

“When it takes off and goes to the side that's a significant amount of distance to travel in a very short period of time, we're talking miles, that thing just goes poof and in about a second it's off the side of the screen.

8 The retired US pilot supports former US intelligence officer Luis Elizondo claims that the existence of UFOs has been proven 'beyond reasonable doubt' Credit: YouTube

"You look at the video of it there's no exhaust flume, there's no indication of how that thing is moving around. Having seen a lot of different airplanes, you can always at least hot spots where the exhaust is coming out. I was close enough visually to go 'we don't have anything like that'."

He insisted the object was alien in origin.

He said: “I know what I saw, it was impressive, it had incredible performance, obviously I wasn’t in a hostile act with it, you’d have your hands full if you were.

8 Retired US pilot David Fravor has called on Stephen Hawking to look into his claims Credit: Getty - Contributor

8 Credit: Getty - Contributor

"I honestly don’t think humans have that technology to do what that thing did. Nor could the human body withstand accelerations like that. It’s an incredible technology to be able to go up to space, and back down and hang over the water.

"I know what I saw and the other three people that were there saw at the same time. I think you would be hard pressed to question my credibility flying experience wise. I’m totally sane, in good health, I don’t do drugs.

"We physically saw and chased it and are the only ones that have actually got close to one of these things.”

8 Retired US Democratic Senator Harry Reid set up the Department of Defense programme Credit: Reuters

Fravor is now calling on British space expert Stephen Hawking to view the video and give his take on it.

He said: “They should be talking to Stephen Hawking. He’s a brilliant man, I would like to hear his thoughts on it. They said they’re talking to some other theoretical physicists like him about the possibilities.”

What the retired US pilot claims to have seen; - The UFO was shaped like a 40ft long white “tic tac” sweet with no windows, wings or visible exhaust flume - It jammed the radar of another F18 fighter jet tracking it - As he flew within half a mile of it, the UFO mirrored his plane's movements - It shot off at a speed no known aircraft on earth could fly at disappearing in "a second" - His colleague was called to the Pentagon six times in the last year to be interviewed about it - He wants British scientist Stephen Hawking to analyze the video now it is public - He thinks the human race must take UFO sightings seriously in case of a hostile alien visit

And in a stern warning to governments around the world he added: “We all need to take these seriously as a species, because right now we don't know the intent of these things, if they're like ET it's great, if they're like War of the Worlds not so much.

“You can ignore them and hope they're just going to observe, or you can do something about it and try to understand what they’re doing and develop technology, in case they do have a bad intention.”

In another video released by the US government into the existence of extraterrestrial life a pilot can be heard muttering: "This is a f****** drone, bro," the New York Post reported.

United States navy pilots encounter bizarre UFO in video released by US the Department of Defense

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The footage shows another pilot saying: “There’s a whole fleet of them,” before exclaiming, “It’s rotating!”.

The footage captures a glowing whitish oval and a darker orb as the jets, dispatched from the aircraft carrier Nimitz, chase the craft.

The footage was released by the Defense Department’s Advanced Aerospace Threat Identification Program, which spent $22 million between 2008 and 2012 to investigate reports from military and commercial pilots of unidentified flying objects.

A version of this story originally appeared in the New York Post.

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