Former National Security Adviser Herbert Raymond McMaster, who served under Donald Trump, has weighed in on unidentified flying objects, calling some phenomena "inexplicable."

McMaster made the remarks on Friday during an episode of Real Time With Bill Maher, after the host asked about the existence of extraterrestrial life on Earth.

"Years ago, when there were UFO sightings, it was some farmer in the middle of nowhere. Now it's Navy personnel," Bill Maher said.

Maher added that if aliens existed, the president would have to be informed when entering office. "Trump was president. He would have blabbed it by now," he said, before asking McMaster, "What do you think?"

"There are things that cannot be explained. I don't know what the explanation is for those unexplainable things, but I will say that there are phenomena that have been witnessed by multiple people that are just inexplicable by any kind of science available to us," McMaster said.

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