In an interview in July, Reeves spoke about pitching the movie to Warner Bros.
"What they said was, 'Look, it's a standalone, it's not part of the extended universe,'" Reeves said at the time.
However, in a series of tweets, Reeves has now made it clear that the new "Batman" film exists in the DC universe.
"Just to be clear: Of COURSE Batman will be part of the D.C. Universe. Batman will be BATMAN," he wrote.
He went on to post, "In my comments from a while back about not being part of the DCEU, I was talking about The Batman being a story specifically about Batman... Not about the others in the Universe.
Initially the film was to be written and directed by Ben Affleck, who currently plays the Caped Crusader in the DC films.