Prince William says he wishes Princess Diana could have 'seen the children grow up'

Prince William misses his mom.

The 34-year-old royal gets candid about the late Princess Diana, nearly 20 years after her death, in the newest issue of British GQ.

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"I would like to have had her advice. I would love her to have met Catherine and to have seen the children grow up," William admits to the publication. "It makes me sad that she won't, that they will never know her."

The prince goes onto explain that because of the very public nature of his mother's tragedy, it has taken him a long time to be able to truly open up.

"I am in a better place about it than I have been for a long time, where I can talk about her more openly," he shares. "It has taken me almost 20 years to get to that stage. I still find it difficult now because at the time it was so raw. And also it is not like most people's grief, because everyone else knows about it, everyone knows the story, everyone knows her."

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Despite his yearning for a private grief, William says he is committed to making sure his children don't grow up too shrouded behind the royal palace.

"I want George to grow up in a real, living environment, I don't want him growing up behind palace walls, he has to be out there," William says. "The media make it harder but I will fight for them to have a normal life."

During the feature, William also discusses mental health, and the Heads Together campaign, an initiative that he and wife Kate Middleton have strongly championed in recent months.

WATCH: Prince William Honors Mother Princess Diana During Inaugural Legacy Awards -- Watch

"Smashing the taboo is our biggest aim. We cannot go anywhere much until that is done," William implores. "I've been really shocked how many people live in fear and in silence because of their mental illness."

The latest issue of British GQ is on stands June 1.

Watch the video above for more of William and Kate's mental health de-stigmatization advocacy.