"I'll play Fox Mulder forever," the actor says on Wednesday's "Tonight Show."

Good news, X-Files fans: David Duchovny isn't ready to say goodbye to Fox Mulder.

The actor, who now stars on Showtime's Californication, says he continues to hold out hope of making a third movie.

"We always want to," he told Jay Leno in an interview on Wednesday's The Tonight Show. "[Creator] Chris Carter and [co-star] Gillian Anderson and I, we're always on board."

Duchovny, who has previously expressed interest in doing a third film, then encouraged fans to start a letter-writing campaign to the studio to make it happen.

"You want to write Fox and get 'em going…," he told the audience, adding: "You could wheel me [out]. I'll play Fox Mulder forever."

The sci-fi series aired on Fox for nine seasons, from 1993-2002, spawning two movies. 1998's The X-Files: Fight the Future grossed about $189 million at the worldwide box office, but the 2008 sequel, subtitled I Want to Believe, earned only $68 million, according to Box Office Mojo. Still, the show continues to have a huge cult following.

Later on The Tonight Show, J.B. Smoove lobbied Duchovny for a role in the potential third film by revealing that he once saw an unidentified flying object.

"I have seen a UFO before, so I could be a great sidekick," he says. "And I had a witness too. That's the best thing. You got somebody next to you to say you ain't drunk."

Watch both clips below.