Brad Pitt was so ''proud'' to have Angelina Jolie by his side at the word premiere of 'World War Z' in London on Sunday night (02.06.13).

The 49-year-old actor - who has six children, Maddox, 11, Pax, nine, Zahara, eight, Shiloh, six, and four-year-old twins Knox and Vivienne - was joined by his 37-year-old fiancee, who made her first red carpet appearance at the Empire Cinema screening in Leicester Square, since admitting she underwent a double mastectomy and reconstruction after she was identified as carrying the BRCA1 cancer gene, increasing her risk of developing breast and ovarian cancer.

Brad told BANG Showbiz: ''I'm always proud to have her by my side. We've got work to do but it's always more fun when she's around.''

Angelina, who spent 20 minutes signing autographs and posing for pictures with fans, stunned onlookers in a flowing Yves St Laurent black silk gown and Brad nodded his head in response to being told she looked beautiful, gushing: ''I so agree!''

The actor also opened up about Angelina's brave decision to undergo the preventative surgery and said he wasn't surprised by her decision to share the news.

He said: ''I was so proud of her before. It's absolutely who she is and she's always been - when faced with a problem, she's going to take it head on. And then she'll make it her own, and find out what her options are, and make the smartest decision for her, and then she's going to share that knowledge with whoever will listen.''

Angelina, who missed her beloved aunt Debbie Martin's funeral in San Diego to support Brad at the screening, was in good spirits and said: ''I'm here for Brad. I'm so proud of him.''

The 'Salt' actress has been in regular contact with her family after losing her aunt last weekend following a battle with breast cancer.

Debbie's husband Ron previously said: ''Angelina will be in London on Sunday so she won't be able to attend but she has been in touch with us and with various other members of the family, which has obviously been lovely and has meant a lot to us.''