Hollywood filmmaker Steven Spielberg’s upcoming alien film Disclosure Day is “more truth than fiction”, he told theatre operators on Wednesday at CinemaCon in Las Vegas.

At the convention, Spielberg described his 1977 UFO film Close Encounters of the Third Kind as his own “speculation” about intelligent life on other planets.

As per Reuters, the filmmaker 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 about Disclosure Day. “And this movie is also going to cause you to ask a lot of questions,” he added.

“All you need to get from the beginning to the end is a seat belt,” he further said, without elaborating on the plot.

Footage from the film was shown at CinemaCon, which offered 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 in theatres on June 12.

The official description of the film on YouTube reads, “If you found out we weren’t alone, if someone showed you, proved it to you, would that frighten you?” It adds, “This summer, the truth belongs to seven billion people. We are coming close to … Disclosure Day.”