The upcoming South Korean war film "Operation Chromite" will pay tribute to the little-known heroes of the Battle of Incheon, producers said Friday.

On Sept. 15, 1950, the U.N. and South Korean forces penetrated Incheon, then captured by the North, through an amphibious invasion. That invasion, known as the Battle of Incheon, saved South Korea from the brink of Korean War defeat and played a decisive role in its victory against the North, according to historians.

"Operation Chromite," directed by John H. Lee, will center on a secret intelligence unit that spied on North Korea to prepare for that historic battle.

"At first, I thought it would be another war movie, but upon reading the scenario, I realized it's more of a suspense thriller," South Korean actor Lee Jung-jae told reporters at a press conference in Seoul. "I decided to take part because it sheds critical light on the sacrifices made by the intelligence unit and people of Incheon."

Lee will play Jang Hak-su, a South Korean naval captain who spearheaded the spy operation called "X-Ray." A total of 17 soldiers were part of the Korea Liaison Office, the intelligence unit.

American actor Liam Neeson, who couldn't make the press conference due to a scheduling conflict, will star as the mastermind of the Incheon Landing, U.S. General Douglas MacArthur.

South Korean actor Lee Beom-soo will be the villain, Rim Kye-jin, who controlled the North's troops in Incheon.

South Korean actor Jung Joon-ho, who will portray a fictional character that led the Incheon branch of the KLO, echoed Lee Jung-jae's comments, saying the film will document a critical part of South Korean history.

"I wanted to help show our future generations how South Korea came to be and how these hidden heroes played a big part," Jung said.

Lee Jung-jae, meanwhile, dismissed anticipation that "Operation Chromite" will be his big break into Hollywood.

"People ask if this will be my Hollywood break, but I tell them it's Neeson's break into K-movies," Lee said, laughing.

John H. Lee, who directed another Korean War film five years ago, said he'd been wanting to shoot another war movie since "71: Into the Fire," a story of South Korean students who fought in the Korean War.

"I remember thinking after '71: Into the Fire' that I want to film another war movie," he said, "the reason being the unique charm and drama of war films. They capture humanity in its direst situations."

"Operation Chromite" will open in July 2016. (Yonhap)