The couple, who have been together seven years and are the parents of six children, previously said they didn't want to tie the knot until gay marriage was legal.
"We'd actually like to [get married,]" he told The Hollywood Reporter, "and it seems to mean more and more to our kids. We made this declaration some time ago that we weren't going to do it till everyone can. But I don't think we'll be able to hold out. It means so much to my kids, and they ask a lot. And it means something to me, too, to make that kind of commitment."
Asked if he has proposed to Jolie, Pitt replied, "I'm not going to go any further."
"But to be in love with someone and be raising a family with someone and want to make that commitment and not be able to is ludicrous, just ludicrous," he said.
Pitt was nominated for an Oscar this week for his work in the film "Moneyball." He was previously married to actress Jennifer Aniston.