Margot Robbie has wanted to make Birds of Prey since she began filming Suicide Squad in 2015.

The Australian actress debuted her unhinged character Harley Quinn in the 2016 ensemble anti-superhero movie, which was directed by David Ayer and starred Will Smith, Jared Leto, Viola Davis, and Jai Courtney.

And she knew she wanted to further explore the former psychologist-turned-criminal while playing the DC Comics character for the first time, as she believed there was a gap in the market for a strong female action hero.

"I love action films, and I think there’s a misconception perhaps subconsciously for people: action films are for dudes, girls don’t really like them," the 29-year-old told Variety. "Which is just not true. I love them! I know heaps of other women who love them.

"I loved movies like the Cameron Diaz, Drew Barrymore, Lucy Liu Charlie’s Angels growing up. So I knew I wanted to find that, and help put that on screen somewhere.”

She then turned to the Birds of Prey comics, which sees Harley joining forces with Black Canary, Helena Bertinelli, and Renee Montoya to take down a narcissistic crime lord, and became "obsessed" with them.

"It seemed like a good platform for a female ensemble franchise, because so many different characters come in and out of the Birds of Prey. And Harley is an easy character to insert into almost any situation, because no matter what, she’s gonna just stir s**t up," Margot laughed.

The Oscar-nominated actress also lavished praise on Todd Phillips' Joker, in which Joaquin Phoenix portrays the iconic Batman villain, who dates Harley Quinn in the DC Comics.

"He did a phenomenal job," she gushed.