South Korean actress Ha Ji Won pinched herself for days when she was cast in John Woo's new action movie Manhunt.

The 39-year-old star, who plays the assassin Rain in the film, tells The Straits Times in Korean via a translator: "I felt like I was dreaming. I just couldn't believe that I would get to work with John Woo.

"I had to pinch myself for three days to remind myself that it was true."

She adds: "My friends were all really jealous when they found out about the casting. They all know who he is and kept asking me so many questions about him."

The gushing comes easily for the actress, who proclaims to be a "big, big fan" of the Hong Kong film-maker's work.

"I've seen all his films. My favourites are A Better Tomorrow and The Killer," she says, referring to his 1980s films.

"He's such a great director that I feel like there is an aura about him no matter where he goes. But once you get to know him, you realise that he's actually a very sweet and romantic person."

Ask her why she loves his films so much and she credits the visual poetry of his action films as the main draw.

"He has this way of filming action sequences that makes them look more like beautiful dance forms.

"His action scenes flow like water. I wanted to make sure that I conveyed that smooth flow in my own action scenes, so I worked on my flexibility through jiujitsu and ballet for three months before shooting."

Her role of Rain is special as this is the first time Woo has included a female killer in his films.

Well, two, to be exact, as Rain partners another female assassin, Dawn, in the film - a role played by Woo's daughter, Angeles, 37.

Ha lights up again at the mention of her co-star.

"As soon as I met Angeles, I felt like we had known each other for a long time. She is so warm, kind and professional, I felt like I was acting alongside a sister."

In any case, she feels honoured to be playing one of Woo's first two female assassins, she says.

"Nowadays, women have a much stronger image, so that might be why John Woo chose to have female killers this time around."

The actress had so much fun in the role that she hopes to be considered for more action movies.

Not that she is putting her romantic roles behind her.

Ha, who made her name with roles in hit television series such as the romantic comedy Secret Garden (2010) and the palace drama Empress Ki (2013), muses with a laugh: "Maybe I can act in a romantic action movie or drama next. For example, I can play a spy in love.

"Of course, I would love to work with John Woo again, so can you tell him to cast me in a romantic action movie?"