The scientist and military intelligence officer leading the Pentagon's task force for unidentified anomalous phenomena (UAPs) -- which the public calls UFOs -- says being caught off guard by "intelligent or extraterrestrial technical supremacy" remains a top concern as investigators analyze more than 800 cases of mysterious sightings reported by U.S. military personnel dating back decades.
"Data and science has to guide where you go, and we will follow the data," Dr. Sean Kirkpatrick said last month, in an exclusive first interview after his appointment to the All-Domain Anomaly Resolution Office, or AARO.
Congress established the office last year to coordinate efforts across federal agencies to "detect, identify and attribute" mysterious objects of interest in the air, in outer space and underwater, with special focus on mitigating potential threats to military operations and national security.
"The most common misconception is that (the possible phenomena) are all the same thing and they're all extraterrestrial, and neither of those are true," Kirkpatrick said.
"We have to go through the rigor of taking each one, matching it against our known objects and catalogs and then reviewing that -- peer reviewing that -- and making sure that everybody's in agreement," he said of the process, which has included establishing a government-wide data collection initiative.
The AARO has looked into some high-profile UAP sightings, highlighted in congressional hearings, including a 2019 video recording taken by Navy sailors of glowing triangles floating above them.
The vast majority of cases reviewed since the office was established are "readily explainable," Kirkpatrick said, noting that final, evidence-based determinations remain slow and ongoing.
Many reported phenomena are later attributed as likely balloons, drones, debris or animals, such as large birds, he said.
That 2019 video was later determined to be ordinary drones distorted by night-vision goggles.
"I have a full range of hypotheses: On one end of the spectrum, it's advanced technology that's coming from an adversary. Right in the middle, I have all my known objects -- balloons and drones and birds and whatnot. And then on the far end of the spectrum, we have extraterrestrials," said Kirkpatrick.
A small number of the reports -- roughly 2-5% of cases -- are unexplained anomalies, including the so called 2004 "Tic Tac" incident.
"It's really hard to guess on this, and I don't like to guess," Kirkpatrick said of the case. "The more things that I see that resemble a Tic Tac, then I can get more and more information about what that is."
Sixty-five percent of Americans believe intelligent life exists beyond earth, according to a 2021 Pew Research Center survey. A majority -- 51% -- also said then that UAPs under investigation by the government are likely proof of contact.
"I can't rule it out, but I don't have any evidence," Kirkpatrick said.
The House Oversight Committee announced earlier this week that it will hold a hearing on the phenomena on Wednesday as Republican lawmakers pursue unproven whistleblower allegations that the government is secretly in possession of "intact and partially intact" alien spacecraft, which the Pentagon has said is unsubstantiated.
Two former government intelligence analysts came forward last month alleging that details of the alleged craft are being illegally withheld from Congress and the American people. Neither has publicly provided any evidence to substantiate their claims.
"We've interviewed almost 30 individuals who have come in to provide their testimony. And out of all of those, none of it has yet led to any verifiable information that substantiates the claim that the U.S. government has those ships or has a reverse engineering program either in the past or currently," Kirkpatrick said when asked about the allegations.
He downplayed the possible existence of a secret program that he is not privy to, saying, "Nothing has been denied us."
"A number of these (whistleblowers) believe and have stated -- and we believe them now -- that they have seen something. And we are investigating," he said.
The proliferation of conspiracy theories spawned by the UAPs has inspired a sense of bipartisan urgency on Capitol Hill.
Senate Majority Leader Chuck Schumer, backed by other top Democrats and Republicans, this month called for greater transparency by the government. Legislation he proposed would force the National Archives to collect and publicly release records related to UAP reports within 25 years of when they were created unless there is a compelling national security concern.
"There is something there -- measurable light, multiple instruments -- and yet it seems to move in directions inconsistent with what we know of physics or science more broadly. And that, to me, poses questions of tremendous interest, as well as potential national security significance," Rep. Adam Schiff, D-Calif., said during a House Intelligence Committee hearing on UAPs in 2022.
Multiple congressional committees have also explored concerns that the mysterious sightings could be evidence of surveillance by other countries.
"My priority is that we understand the full range of threats posed by our adversaries in all domains," Republican Sen. Joni Ernst, R-Iowa, said during an Armed Services Committee hearing on UAPs in April.
For his part, Kirkpatrick is focused on the gathering of facts and evidence. "A lot of these stories, a lot of these allegations, crop up again and again over history," he said. "I'm not going to jump ahead to conclusions until we have more data."
Asked whether he believes intelligent extraterrestrial life exists, Kirkpatrick said: "I think it's statistically unrealistic to think it isn't" and that finding it would be "probably the best outcome of this job."
ABC News' Luis Martinez contributed to this report.