Brad Pitt has confessed he knew his marriage to Jennifer Aniston would never last and has called his high profile break-up from the former "Friends" actress "beautiful".

"It's talked about like it failed - I guess because it wasn't flawless. Me, I embrace the messiness of life. I find it so beautiful, actually," Internet portal Femalefirst quoted the 41-year-old as saying.

"The idea that marriage has to be for all time - that I don't understand," the star said, revealing that he planned to quit acting in a "few years" to start a family.

Vehemently denying any romantic alliance with his "Mr & Mrs Smith" co-star Angelina Jolie, Pitt said he wanted to punch the person responsible for the "nasty" rumour.