Supporting Queen Elizabeth is a "top priority" for Prince William and Duchess Catherine.
The Duke and Duchess of Cambridge are increasing their royal duties this year and are looking forward to celebrate the monarch's 90th birthday.
A source told HELLO! magazine: "They want to play a full role in supporting the Queen's service to the country and to the Commonwealth in her 90th year.
"Supporting the Queen is a top priority for them and they will play a full part in joining her for major events."
It was recently revealed that the Queen is planning to hand over some of her duties to the younger royals.
The 89-year-old royal wants to cut down on her workload and has reportedly decided to pass on her patronage of the All England Lawn Tennis & Croquet Club, which is responsible for Wimbledon, to her granddaughter-in-law, Duchess Catherine.
Catherine's husband Prince William has been tipped to take over the role of patron of the Football Association from his grandmother, while Prince Harry is set to replace Queen Elizabeth as patron of the Rugby Football Union (RFU), while
According to The Sunday Times: "The Queen is understood to be assessing how much time she can now devote to the 628 organisations and charities to which she is affiliated."