Margot Robbie found it ''exciting'' starring alongside Jared Leto in 'Suicide Squad'.

The 26-year-old star worked opposite the 30 Seconds to Mars frontman in the hotly anticipated movie and admits he surprised her every day.

She told ShortList magazine: ''I was ... surprised. I was surprised! There's an understatement! I loved that stuff. Jared was doing half my work for me.

''Harley [Quinn, her character] is very much a part of a relationship. To have such commitment from the other half made my job a thousand times easier, and a thousand times more fun. I didn't know what was going to happen when we got on set. It's exciting to act opposite that.''

Meanwhile, the 'Legend Of Tarzan' star previously revealed she studied Jared, 44, like a psychologist would so she could get to know him as he was always in character.

She said: ''He's in character all the time. I spent a lot of time trying to figure out their relationship. Because he's got this facade up, it was really hard for me to get through to him at first. So I was like, okay, I gotta approach this as if I'm trying to crack the Joker.

''It's a test that psychologists use to determine what mental illness people might have. It's a list of 500 questions or something. Whenever we had time to rehearse or improvise, or even in scenes, I'd just start with those questions ... I'd see which ones would catch him off guard and how, how he'd react, and I'd be like, 'Okay, I'm gonna go for this tactic now.'''