New York - Angelina Jolie says she wasn't looking for a relationship when she began working with Brad Pitt on "Mr. & Mrs. Smith," adding that the couple "remained very, very good friends" after shooting the movie.

Angelina Jolie and Brad Pitt arrive at the world premiere of Jolie's new film 'The Good Shepherd', Dec. 11, 2006 in New York. The film opens Dec. 22. [AP]

Jolie didn't know where Pitt, then married to "Friends" star Jennifer Aniston, was in his personal life, the 31-year-old actress tells Vogue magazine in its January issue, on newsstands Friday. "But it was clear he was with his best friend, someone he loves and respects."

"I think we were both the last two people who were looking for a relationship. I certainly wasn't. I was quite content to be a single mom," Jolie tells the magazine.

"Because of the film we ended up being brought together to do all these crazy things, and I think we found this strange friendship and partnership that kind of just suddenly happened," she says.

Jolie remained "very, very good friends" with Pitt after shooting ended, she says. "And then life developed in a way where we could be together, where it felt like something we would do, we should do."

Pitt and Aniston announced their separation in January 2005. Aniston filed for divorce in March, citing irreconcilable differences. The divorce became final in October.

Pitt denied that Jolie was behind the split.

In late April, photos were published of Jolie and Pitt playing in the sand and strolling on a beach in Africa with her 3-year-old son, Maddox, whom she adopted from Cambodia.

In July, Pitt and Jolie went to Ethiopia, where Jolie adopted a baby girl, Zahara.

Jolie gave birth to the couple's daughter, Shiloh, in Namibia in May.

The actress says it was her children who ultimately cemented her relationship with Pitt as a family.

One day, Maddox "just out of the blue called him Dad. It was amazing. We were playing with cars on the floor of a hotel room, and we both heard it and didn't say anything and just looked at each other."

"So that was probably the most defining moment, when he decided that we would all be a family."

In December 2005, Pitt filed a petition asking to change the names of Maddox and Zahara to Jolie-Pitt to indicate that he planned to become their adoptive father.

But don't expect Pitt, 42, and Jolie to marry, she says.

"We are legally bound to our children, not to each other, and I think that's the most important thing," the twice-divorced actress is quoted as saying.

Jolie also tells Vogue about how motherhood has changed her.

"I think definitely before my son, I was a little nihilistic. But once I adopted Mad (Maddox) I knew I was never going to be intentionally self-destructive again.

"I'm starting to be able to see being 50 years old with the kids graduating from high school, though in my mind we're in the middle of a desert or a jungle with tutors and some local friends."

Pitt and Jolie appeared together Monday in New York City at the premiere of her new film, "The Good Shepherd."