Angelina Jolie and Brad Pitt will always "stick together".

She said: "The film says, ‘Whatever you go through, weather the storm and stick together’. Brad and I have fights and problems like any other couple.

"We have days when we drive each other absolutely mad and want space. So it was kind of a message to each other that we are going to weather whatever comes and stick together."

But the 40-year-old actress admits the film could have been a "disaster" for their marriage if they had just got together.

She told the Daily Mirror newspaper: "There were a few days when we thought this wasn’t the best idea. There were days when we were really worried and it was hard.

"If we had married and were just starting a relationship it would have been a disaster, but because we have been together so long we wanted to see how far we could push our relationship and our love and see if we could work together under very intense circumstances and with very complex issues and see if it would make us better.

"At the end, we came out of it thinking, ‘This was the best honeymoon.'"