UFO whistleblower Luis Elizondo is strengthening his longtime efforts to pressure the U.S. government into revealing its secretive knowledge about UAPs, or Unidentified Anomalous Phenomena. Now that the Pentagon has finally cleared him to tell the full truth about what he knows, Elizondo has dropped several stunning claims in his new book, Imminent: Inside the Pentagon’s Hunt for UFOs, including a story about the government setting up UAP traps to attract the supposed extraterrestrials.

“We had a plan to set up a real big nuclear footprint, something we knew would be irresistible for these UAP,” Elizondo says in a new video posted on Reddit.

Elizondo, a former Pentagon official, makes other startling claims about what he says the government knows about UAPs, including its stewardship of a “Legacy Program” that is “in possession of advanced technology made off-world by nonhuman intelligence.” In other words, the government is still holding on to evidence that aliens have visited us.

In another incident detailed in his book, “several mysterious and luminous orbs” appeared before a group of scientists as they tested a classified device at the White Sands Missile Range in Los Alamos, New Mexico, in 2013. “The orbs moved toward the test site, hovered over the device as if scanning it for intel, then zipped away, brashly flying over the heads of bewildered scientists.” Several eyewitnesses also saw multiple “disc-shaped objects that seemed to know precisely where the device being tested was located.” Elizondo wrote that the incident occurred several times over the following days.

As former head of the Advanced Aerospace Threat Identification Program—a secret government UFO program that monitored unexplained threats to Navy warships and nuclear silos—Elizondo has had some bizarre encounters of his own. He asserts, for example, that he once saw green “luminous orbs” in his house after he began directing the secret office investigating UAPs in 2010.

The Pentagon redacted some sections of the book before it was published, and it is not supporting Elizondo’s claims.

UAPs have a long history of attracting enthusiasts who want to believe there’s an extraterrestrial presence interested in Earth. However, no proof has yet been found of aliens from other worlds, and the vast majority of UAP sightings can be debunked as a number of other, more mundane occurrences. These typically include weather phenomena, drones or advanced human-made technology, or an illusion of super-fast motion.

Still-unexplained sightings remain mysteries simply because there isn’t enough data to analyze them properly, according to longtime UAP investigator Mick West. “The people who are into UFO investigations are so interested because they’re looking for something extraordinary,” West recently told Popular Mechanics. It’s more important to perform a dispassionate analysis of quality evidence, he says. Then you know the truth is indisputable.

Now that the government is releasing more documentation and evidence, UAP enthusiasts hope a fuller picture about unexplained sightings will emerge. Whether Elizondo’s claims indicate a truly extraterrestrial presence or not is still up in the air. In the meantime, he believes the incidents he describes in his book are a “very serious national security issue.”