The couple have confirmed recent reports that Brad had proposed to his partner of seven years - with whom he raises six children Maddox, 10, Pax, nine, Zahara, seven, Shiloh, five and three-year-old twins Knox and Vivienne - although they have not yet set a date for their nuptials.
Brad`s spokeswoman Cynthia Pett-Dante said: "Yes, it`s confirmed. It is a promise for the future and their kids are very happy. There`s no date set at this time.
Angelina was spotted wearing her engagement ring this week and jeweller Robert Procop - who has previously worked with the actress - revealed he had designed the ring with Brad.
A spokesperson for Robert said: ""I can confirm that, yes, Robert Procop did indeed design an engagement ring for AngelinaJolie, designed in collaboration with BradPitt."
Robert added: "Brad had a specific vision for this ring, which he realised over a yearlong collaboration. He wanted every aspect of it to be perfect, so I was able to locate a diamond of the finest quality and cut it to an exact custom size and shape to suite Angelina`s hand. Brad was always heavily involved, overseeing every aspect of the creative design evolution. The side diamonds are specially cut to encircle her finger. Each diamond is of the highest gem quality."
Brad was previously married to Jennifer Aniston while Angelina has been wed twice before, to Johnny Lee Miller and Billy Bob Thornton.