Steven Spielberg described his 1977 UFO film "Close Encounters of the Third Kind" as his own "speculation" about intelligent life on other planets.

His new alien movie, "Disclosure Day," will offer what Spielberg believes is "more truth than fiction," the veteran filmmaker told theater operators on Wednesday at the CinemaCon convention in Las Vegas.

The maker of "E.T." and 2005's "War of the Worlds" said he decided to journey back into the extraterrestrial realm after reading a 2017 New York Times report about U.S. military pilots who reported seeing mysterious flying objects.

"I really, truly believe this movie is going to answer questions," Spielberg said of "Disclosure Day." "And this movie is also going to cause you to ask a lot of questions."

"All you need to get from the beginning to the end is a seat belt," he teased, without elaborating on the plot.

Footage shown to the CinemaCon crowd gave a brief glimpse of an alien leaning over a human child. The film stars Emily Blunt, Josh O'Connor, Colman Domingo and Colin Firth.

"Disclosure Day" will be released by Universal Pictures CMCSA.O in June.

Universal also brought out another acclaimed director, Christopher Nolan, to promote his upcoming film "The Odyssey." The movie, set to debut in July, is based on Homer's epic about a Greek king trying to return home after the Trojan War.

"The Odyssey is a story that has fascinated generation after generation for 3,000 years," he said. "It is not a story. It's the story."

The "Oppenheimer" director said "The Odyssey" was "an absolute nightmare to film, but in all the right ways."

Star Matt Damon, who plays Odysseus, endured rough conditions throughout the project, Nolan said.

"He was just there, out there on the boats, up in the mountains, in the caves, in beating sunshine, in sideways rain, wind," he said.

"It's meant to be difficult. That's the nature of the story."

-Reporting by Lisa Richwine; Editing by Kevin Buckland/Reuters