The actress makes her first public appearance after announcing she underwent a double mastectomy in February
Credit: Richard Young/Rex/Startraks

Angelina Jolie is back on the red carpet.

Making her first public appearance since revealing she underwent a double mastectomy in February, Jolie, 37, walked the red carpet in a Saint Laurent dress with fiancé Brad Pitt at the London premiere of his film World War Z on Sunday.

On May 14, Jolie announced she had been diagnosed with a mutated BRCA1 gene predisposing her to cancer and had undergone the preventive mastectomy on Feb. 16 and reconstructive surgery on April 27 in an op-ed in the New York Times.

“I do not feel any less of a woman,” she wrote. “I feel empowered that I made a strong choice that in no way diminishes my femininity.”

Since then, Jolie has spent time recovering at home in Los Angeles while preparing to direct Unbroken, a film based on the bestselling book by Laura Hillenbrand about a World War II hero’s amazing survival story.

Pitt, 49, has publicly voiced his support of Jolie, calling her decision to undergo the double mastectomy “absolutely heroic.”

At the premiere, which the couple attended with sons Maddox, 11, and Pax, 9, Pitt told PEOPLE how proud he is of his partner.

“I think the world of her, she is an amazing woman,” he said. “She wasn’t really nervous about coming to support me tonight, she was so moved – we were all so moved – by how much it meant to others.”

He continued, “We didn’t realize, or certainly I didn’t realize, how many people were in limbo over this, deliberating, and unsure of what their options were. They didn’t know the testing even existed, then you find out it is not available to everyone. It certainly should be, there is no reason for anyone to have to die. It’s become a tipping point. I’m very touched by the reaction, it makes me very emotional.”

As she entered the theater, Jolie told the BBC she’s “feeling fine” and she’s grateful for all the support.

“I’ve been very happy just to see the discussion about women’s health expanded and that means the world to me. After losing my mom to these issues, I’m very grateful for it and I’ve been very moved by the support from people.”

World War Z producer Dede Gardner recently commented on how the couple’s relationship will endure the trying time.

“With Angelina, he’s got a great partner,” she said. “They treat each chapter as the next leg on their journey.”

Following Sunday’s Leicester Square premiere, Muse – who is featured on the film’s soundtrack – will perform in St. James’s Park.

World War Z opens in theaters June 21.

• With reporting By NADIA COHEN