He revealed that his experience making the latter film was a big factor in his decision, stating that the production was plagued with issues.
"I had a better time on Batman v Superman which I really enjoyed doing. Justice League was unfortunately touched by personal tragedy, a death in Zack [Snyder's] family," Affleck said. "Sometimes things work and gel and sometimes you seem to just be having one problem after another."
After Snyder left the project for tragic personal reasons, Avengers director Joss Whedon was brought in to finish Justice League and reportedly carried out extensive reshoots.
More like this
Fans were generally disappointed by the end result and Affleck too felt burned out afterwards.
He added: "I sort of had my fill of that. They said 'do you want to direct and star in a solo Batman movie?' I found that I had kind of lost my enthusiasm or passion for it.
"This should really be made by someone for whom it's their wildest dream come true and, for me, it had become something different. It was clear that it was time to move on."
The film co-stars Zoe Kravitz, Paul Dano and Colin Farrell as iconic rogues Catwoman, Riddler and Penguin, as well as Andy Serkis and Jeffrey Wright as allies Alfred Pennyworth and Commissioner Gordon respectively.
The Batman is scheduled for release on 26th June 2021