Siwan talks about his group ZE:A, being an actor and his new film The Merciless

The Merciless will premiere on May 17 in Korea.

Siwan's scene in The Merciless CJ Entertainment

Korean boy band ZE:A member Siwan is more popular today as an actor than being a K-pop idol.

He and fellow actor Seol Kyung-goo are starring in the film "The Merciless," which will premiere on May 17 in Korea and will be shown out of competition at the 70th Cannes Film Festival slated from May 17 to 28.

Siwan has been invited to Cannes but he is unsure if he will be attending because of the filming of his new TV drama "The King Loves."

"I didn't know exactly about Cannes except that it's one of the three largest film festivals in the world. I wonder what kind of turning point in my life it would be that I appeared in a Cannes-bound film," he told Yonhap News.

He plays a tough guy in the movie, which he said "was so cool that I did not have to pretend to be good on screen. I felt like I slipped off a layer of my skin."

The 28-year-old star made his acting debut in the hit TV drama "Moon Embracing the Sun" in 2012.

"(I) felt that acting fits my aptitude quite well. Before, I just vaguely longed for acting," he said. "After finishing the drama I thought I'd like to do more acting if there is any chance. And I've got many good opportunities so far, fortunately."

After that, he starred in other TV dramas including "Man From the Equator," "Standby" and "Misaeng." He also did movies such as "The Attorney" in 2013.

Siwan felt honored to have worked with great Korean actors such as Song Kang-ho, Lee Sung-min and Seol Kyung-goo, saying "I think I grew a lot from this."

He has been focusing on his solo career for years as ZE:A has been on hiatus. The boy band's last album was "First Homme" released in 2014.

Three members of the group, Minwoo, Taeheon and Kwanghee, are also serving in the army. Siwan is also expected to enlist in the coming months.

He said because of military service, it will be hard for ZE:A to regroup.

"I think reassembling entirely will take at least several years because members need to go to the Army," he said.

Despite this, Siwan wants to continue his singing career.

"I'd like to release a single album, sing soundtracks for dramas and hold a fan meeting if time permits. But I'm not sure if I can afford time to do them," he said.