Former U.S. President Barack Obama said he did not see evidence that aliens “have made contact with us,” after sending social media abuzz by saying aliens were real on a podcast over the weekend.

During a lightning round of questions with podcast host Brian Tylor Cohen, Obama was asked, “Are aliens real?”

“They’re real,” he answered, continuing: “But I haven’t seen them. And, they’re not being kept in Area 51.”

On Sunday night, the former president released a statement on Instagram, appearing to clarify what he meant by his comments that have since gone viral.

“I was trying to stick with the spirit of the speed round, but since it’s gotten attention let me clarify. Statistically, the universe is so vast that the odds are good there’s life out there. But the distances between solar systems are so great that the chances we’ve been visited by aliens is low, and I saw no evidence during my presidency that extraterrestrials have made contact with us. Really!”

Secrecy around Area 51, a top-secret Cold War test site in the Nevada desert, has long fueled conspiracy theories among UFO enthusiasts.

In 2013, the CIA acknowledged the existence of the site, but not UFO crashes, black-eyed extraterrestrials or staged moon landings.

Declassified documents referred to the 8,000-square-mile (20,700-square-kilometer) installation by name after decades of U.S. government officials refusing to acknowledge it.

The base has been a testing ground for a host of top-secret aircraft, including the U-2 in the 1950s and later the B-2 stealth bomber.