The studio is also representing disaster drama Sinkhole, fantasy drama Our Season, action comedy The Golden Holiday and the Lee-starring spy drama The Man Standing Next.
Showbox is handling pre-sales for the project and will open it up to distributors at the European Film Market this week.
Emergency Declaration is currently in pre-production and is eyeing an end-of-year release.
Jeon is best known for her performance in the 2007 drama Secret Sunshine, for which she won a best actor award at Cannes, and is also known for starring in Untold Scandal and The Housemaid.