(NewsNation) —  The subject of UFOs is one that has sparked questions for decades and recently been in the headlines over allegations that the Pentagon is covering up a program to retrieve such objects. But one question remains: Where are UFOs coming from?

Pentagon insider Luis Elizondo told NewsNation that while many people believe UFOs (or, as the government prefers to call them, “UAPs”) are originating from outer space, that is not necessarily a given.

“I often tell people, they can be from outer space, inner space or, frankly, the space between,” Elizondo said.

Elizondo told NewsNation’s Ross Coulthart that UFOs could be natural, perhaps from the oceans.

“We’re discovering new life all the time,” he said. “Is it really that implausible? We discovered two new species last week.”

Just because something isn’t human doesn’t mean it’s alien, Elizondo said, and what we once considered fantastic may later become a matter of real science.

“Remember when we started sailing the ocean blue they said, ‘Oh the earth is flat, and you’re gonna fall off. And people said there were sea monsters; we laugh about that now,” Elizondo said. “But you know what, there are. They’re called blue whales and great white sharks and the giant squid of the Pacific.”

The Pentagon has denied Elizondo had any information on UAP investigations.

“As we have stated previously, Luis Elizondo had no assigned responsibilities for the Advanced Aerospace Threat Identification Program (AATIP) while assigned to the Office of the Under Secretary of Defense for Intelligence and Security,” said spokesperson Sue Gough.

“The department is fully committed to openness and accountability to Congress and the American people, which it must balance with its obligation to protect sensitive information, sources, and methods. As we have said many times before, the department and AARO will follow the data wherever it leads; however, to date we have not found any credible evidence of extraterrestrial activity.

“I refer you to the Historical Record Report Volume 1, available on www.aaro.mil. AARO continues its review of the historical record of U.S. government UAP programs and intends to publish a Historical Record Report, Volume Two. To date, AARO has not discovered any verifiable information to substantiate claims that any programs regarding the possession or reverse-engineering of extraterrestrial materials have existed in the past or exist currently. AARO welcomes the opportunity to speak with any former or current government employee or contractor who believes they have information relevant to the historical review.”

UAP believers have pushed back on the denial, pointing to evidence they believe proves that Elizondo was involved with AATIP and say the Pentagon is running a disinformation campaign.