Speaking at a keynote session at the SXSW Film & TV Festival in Austin, the director said he has long suspected that humans are not alone in the universe. "I don't know any more than any of you do, but I have a very strong suspicion that we are not alone here on Earth right now," Spielberg said.

The director, whose films include E.T., Close Encounters of the Third Kind and War of the Worlds, added that the idea of alien life has fascinated him since childhood. "I've always been fascinated with things that cannot be explained," he said in a behind-the-scenes video for his upcoming project Disclosure Day. "When I was just a little kid, I remember developing a real curiosity about the sky at night and also not the possibility but the guarantee that there is life off this planet."

During the SXSW conversation, Spielberg also referred to remarks by former US president Barack Obama, who had said that given the vastness of the universe, the odds of life existing elsewhere are high. "He stepped back to say what he believed was life in the cosmos, which, of course, everybody should believe in," Spielberg said. "No one should really think that we are the only intelligent civilisation in the entire universe."

At the same time, the filmmaker acknowledged the question of whether extraterrestrial life has visited Earth remains unresolved. "The big question is, are we alone now? And have we been alone over the last 80 years?"