Credit: CBS; Chris Jackson/Getty Images

It's not easy finding the perfect gift for the couple who has everything.

Prime Minister David Cameron, 44 -- who is expected to attend Prince William and Kate Middleton's wedding on Friday -- tells CBS Evening News' Katie Couric that he chose a non-traditional present for the future spouses.

"[William] is currently serving in Anglesey, which is a small island off the coast of Wales where he does search and rescue, flies a helicopter," Cameron explained. "I've got him a present to do with Anglesey."

"It's a lovely book and beautiful photographs and things like that," he continues. "So that's what I'm giving."

Other notable wedding guests include Joss Stone, Sir Elton John, David and Victoria Beckham, director Guy Ritchie, Mr. Bean star Rowan Atkinson and British television presenter Ben Fogle.

Couric's full interview with Cameron airs Wednesday on CBS at 6:30 p.m. EST.

For more on the Royal Wedding, including rare photos, interviews with family and friends, details on Kate's new life as a princess and a tour of their lavish homes, order a copy of Us Weekly's Will & Kate: The Royal Wedding now.