A US online website released the news.
Karukoski says he would have preferred the announcement to remain secret, but the film's US production company, PalmStar, wanted to quash online speculation surrounding the choice of director.
A script by writer Matt Harris entitled The Starling will be used to produce the movie. The director terms the film as a 'comedy about sorrow.'
"It's one of the best scripts I have read in years," Karukoski says.
Superstar Keanu Reeves and Australian comedy actress Isla Fisher are pegged to headline the flick.
According to Karukoski, the two actors seem invested in the project, but contract talks are ongoing.
"Agents negotiate with agents in Hollywood," said Karukoski, likening such talks to buying a house.
Karukoski has been invited to Hollywood before. International interest in him spiked after his 2013 film, Heart of a Lion. The movie was about a neo-Nazi who changes his ways for the sake of a biracial child.
The director has however declined all offers, until now.
Karukoski has been on record saying that he does want to be a wheel in a huge Hollywood machine, doing nothing more than yell 'action' and 'cut.' He wants to have complete control, and PalmStar came closest to agreeing to his terms, giving him a say in the casting.
Karukoski is currently marketing his newest film, Tom of Finland.