DeLonge quit his band Blink-182 in 2015 to focus on his search for extraterrestrials and founded his own aerospace-science-entertainment company To the Stars two years later to probe deeper into the matter.
Now, the star says his organisation have briefed America's leader on their findings.
"I don't know what he knows, but I do know that we helped set up briefings for the White House," he tells The Guardian newspaper.
The "Miss You" hitmaker also claims past presidents have come close to going public with secret information on alien life.
"I can't say much," he adds. "But I do know there have been moments when certain presidents have come close. The issue always becomes: how are people going to digest this if we hit them over the head with a giant sledgehammer? That's scary for people in the Pentagon when they're trying to keep civilisation duct-taped together."
The star also believes in alien abductions - saying they are a fact of humanity's history.
"Abductions have been around since the dawn of time," he muses. "Cave drawings show the exact same entities that people see in so-called abductions. People who use psychedelic drugs to help with post-traumatic stress syndrome, depression and anxiety all see these same beings, these same entities."
"People say these abductions take place in their sleep. I think people are going to find out that this has a lot to do with consciousness and it's not just coming from another planet. There's a lot more to the universe."