Angelina Jolie's engagement ring could be worth as much $1 million.

The Hollywood actress and her partner Brad Pitt confirmed they are getting married at the end of last week. They have been together for around seven years and raise six children.

It is known that Brad had a big hand in designing the ring he has presented Angelina with, which she was spotted wearing at an event earlier this month.

It was created by Beverly Hills jeweller Robert Procop and features a number of diamonds and a yellow gold band. Initially it was reported that it set Brad back $250,000, but People magazine claims the true cost could have been a lot more.

"An independent expert [says] that the ring could weigh in at more than ten carats total, with a price tag of $1 million," reports the publication.

Brad and Angelina have previously spoken about their wedding plans, with Brad admitting their children were starting to pester them about tying the knot.

"They've reached a stage where their family has jelled," an insider explained.

Jeweller Robert discussed how he and Brad came up with the ring design recently. He explained the Hollywood hunk was determined to get the band right and didn't mind how long it took to design.

"Brad had a specific vision for this ring, which he realised over a yearlong collaboration," he told The Hollywood Reporter. "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 suit 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."