Prince William says it took him 20 years to open up about his mother's death

London: Britain's Prince William has said that it has taken him 20 years to open about his mother's death, as he lamented that his wife Kate Middleton and children will never meet Princess Diana.

The Duke of Cambridge, whose mother Diana, Princess of Wales, died 20 years ago in August, said he would like to have had her advice.

"I would love her to have met Catherine and to have seen the children grow up. It makes me sad that she won't, that they will never know her," the 34-year-old British royal told the GQ magazine in a candid interview to publicise charity Heads Together.

William said it has taken nearly 20 years for him to become comfortable speaking about his mother's demise.

Talking about the imminent anniversary of his mother's death, he said, "I am in a better place about it than I have been for a long time, where I can talk about her more openly, talk about her more honestly, and I can remember her better, and publicly talk about her better."

"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," the second in line to the throne said.

The interview comes as Prince William and wife Kate have thrown their weight behind the Heads Together campaign, encouraging people to speak about their mental health.

"Smashing the taboo is our biggest aim. We cannot go anywhere much until that is done. People can't access services till they feel less ashamed, so we must tackle the taboo, the stigma, for goodness sake, this is the 21st century," he said.

William also stressed the importance of family, saying that he would not be able to do his job without the stability of the family.

"Stability at home is so important to me. I want to bring up my children in a happy, stable, secure world and that is so important to both of us as parents," he said.

"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. The media make it harder but I will fight for them to have a normal life," the prince said.

Significantly, William's remarks come following reports that Queen Elizabeth II told Prince William and Prince Harry to stop "soul-baring" and be more stately like their grandfather.