Brad Pitt and Angelina Jolie pose on the red carpetReuters

Actors Angelina Jolie and Brad Pitt keep the spark alive when working on separate projects.

The 39-year-old actress was directing Unbroken, the biopic of war hero Louis Zamperini, in Australia and Brad was starring as a soldier fighting the Nazis in Fury in London. They still found a way of staying close.

Jolie has revealed to Australia's Tv Week magazine that she and husband Pitt wrote handwritten love letters while filming in different continents.

The Salt actress said, "Brad Pitt was supportive from a distance and it was quite romantic in a way."

"We decided to be of that time when we could imagine he was in the European theatre and I was in the Pacific theater and we wrote hand-written letters to each other that were very connecting for us, thinking of the people that were separated for months if not years at a time back then."

She also talked about her surgery in 2013 for a preventive double mastectomy, and revealed the caring and supportive side of the Inglourious Basterds actor.

"He wanted me to make the movie to show something hopeful about the strength of the human spirit that can pull us through. He reminded me to have my surgery in the year that I did, and he reminded me to appreciate every day of my life," Jolie added.

Jolie told the magazine that she is lucky to meet the World War II hero, Zamperinia, on whom her movie Unbroken is based, and also showed him a rough cut of her movie Unbroken before he died earlier this month, reported ABC News.

"I brought him the film on my laptop in the hospital, and it was amazing seeing someone at the end of their life watching their life unfold again, at the same time their body was shutting down," she recalled.

The engaged couple, who met while co-starring on 2005's Mr. and Mrs. Smith, will reunite onscreen in an upcoming film By The Sea.

Unbroken starring Jack O'Connell as Zamperinia is scheduled for release on 25 December, 2014.

Click to watch the trailer of Unbroken