Margot Robbie is "so happy" Lady GaGa is set to play Harley Quinn in 'Joker: Folie a Deux'.

The 32-year-old actress - who played the character in 'Suicide Squad' (2016), 'Birds of Prey' (2020) and 'The Suicide Squad' (2020) - loves the idea of the iconic role being passed around "great actors", with each getting the chance to share their own take on the comic book creation.

She told MTV: "It makes me so happy because I said from the very beginning, all I want is for Harley Quinn to be one of those characters, the way Macbeth or Batman always gets passed from great actor to great actor.

"And I feel like in not so many cases are they female characters.

"Queen Elizabeth I, but like beyond that — which I got to have a crack at as well, which I was honored to do. I was like, 'Wow, Cate Blanchett did Queen Elizabeth I. Now I get to.' "

And Margot is looking forward to see the "incredible" way Gaga will bring the character to life, though her exact role in the 'Joker' sequel opposite Joaquin Phoenix hasn't been confirmed.

She added: "It's such an honour to have built a foundation strong enough that Harley can now be one of those characters who other actors get to have a go at playing. And I think she'll do something incredible with it."

Margot has previously admitted she had no plans to reprise her role as the psychiatrist-turned-vigilante in another film because she needed a "break" from playing the "exhausting" character.

She said last year: "I was like, 'Oof, I need a break from Harley, because she's exhausting.' I don't know when we're next going to see her."