Luis Elizondo offers window into US government's hunt for UFOs

Longtime Defense Department researcher Luis "Lue" Elizondo has become well-known for reporting the existence of UFOs (unidentified flying objects), now known as unidentified anomalous phenomena (UAPs).

In his new book, "Imminent: Inside the Pentagon's Hunt for UFOs," which is available now, former Pentagon insider Elizondo invites the reader into this hidden world.

He joined ABC News' Stephanie Ramos to discuss why he decided to write the book, government secrecy around UAPs, official comments on these phenomena and some of his own unusual experiences.

ABC NEWS: Unidentified flying objects have fueled decades of speculation and conspiracy theories. In his new book, "Imminent: Inside the Pentagon's Hunt for UFOs," longtime Defense Department researcher Lue Elizondo, the former head of the Pentagon program responsible for the investigation of UFOs, now known as unidentified anomalous phenomena, reveals long hidden truths with profound implications for not only national security, but our understanding of the universe.

Joining us now is Lue Elizondo. Thank you so much for joining us. Really appreciate it. So "Imminent" tells the story of your courageous fight to make public what the government knows and doesn't know about UAPs. What made you want to write about this?

ELIZONDO: Yeah, well, I wanted to be able to tell the American public my experiences and what the government has been doing for a very long time, not just when I was in the program, but for decades about the government's interest in UFOs or now what we call UAP. You're absolutely right, unidentified anomalous phenomenon. The fact is, they're real and they are a national security issue for this country.

ABC NEWS: And it's so interesting because many, many years ago I worked at the Pentagon for ABC, and I remember getting a tour of some of the hallways and, and somebody said "Oh, that's where they study UFOs, UAPs. But it's top secret." Like that's all they would say. So there's this secrecy approach to all of this, right?

You write in your book, "While there are valid reasons for secrecy around some aspects of UAPs. I do not think humanity should be kept in the dark about the fundamental fact that we are not the only intelligent life in the universe." So why do you think the United States government and other major governments have taken a secrecy approach to UAPs?

ELIZONDO: Sure. I think if we look at this, temporally speaking, the U.S. government, when we started really looking at this, was at the height of the Cold War. And you had this contentious relationship at best with then-Soviet Union.

And what we didn't want to do was necessarily tip our hand to any information, perhaps, that we've gleaned from UAP or UFOs and, certainly, perhaps any information gaps or maybe information that we don't know about the UFOs. So that's one reason. And then I think the other reason is that governments inherently are responsible for ensuring the protection of their people, their citizens.

ABC NEWS: So Lue, for those who may be skeptical and are thinking "Nope, there's no such thing as UFOs, it's non-existent." And you're here to tell us that there is fact and research that they do exist.

ELIZONDO: Let's not forget, Stephanie, that we've had already a former director of national intelligence, a former director of the CIA, and even a former president of the United States all come out on the record and say "Yeah, looks like these things are real."

Our very best, most sophisticated technology is picking these things up. We also have eyewitness testimony from our trained observers, our combat pilots. And then you've also got the radar data all basically substantiating the same event at the same time, at the same place, under the same circumstances.

ABC NEWS: And so much technology that's been analyzed and researched. Now, let's talk about your own personal experience. You mentioned in this book that UAPs have appeared both in and around your home. How did these personal experiences influence your views on UAP and what exactly did you see?

ELIZONDO: Yeah, sure. So first of all, let me preface. We're not sure if they are actually UAP-related. What we do know is that a lot of people that were in the program that I was in also had very similar encounters while they were in the program.

So not before or not after, but during the time that we were researching these UAP and from our experience, when I say ours, I mean my families and even our neighbors, witnessed some of these – are these luminous green balls of light. Very diffuse in nature. No hard edges. That would just seem to kind of peruse the house and go down the hall and go through a wall.

I know it sounds rather bizarre. And look, there are absolutely possible natural explanations, right? You could say ball lightning or Saint Elmo's fire or some sort of plasma static charge in the air. But the bottom line is, it was very bizarre. It was witnessed by not only my family, but again, neighbors and other individuals who were part of our effort, and the government, also experienced, very, very similar encounters at their residences.

ABC NEWS: Absolutely fascinating. Thank you so much Lue, for sharing your experience and for documenting what you know and what you think we should all know in your book, "Imminent: Inside the Pentagon's Hunt for UFOs," which is available now to purchase. Thanks Lue.

ELIZONDO: My honor and privilege. Thank you.