Prince Harry has said he hopes to "share the spirit" of his mother with his children on the 25th anniversary of her death next week.
Diana, Princess of Wales died in a car crash in Paris on 31 August 1997 with her lover, Harrods heir Dodi Al-Fayed.
As the quarter-century anniversary of her death approaches, the Duke of Sussex gave a speech at a dinner for the African HIV charity he co-founded called Sentebale.
"My dear friend Prince Seeiso and I founded Sentebale 16 years ago in honour of our mothers, with a mission to support many of the most vulnerable young people on the planet - and to give them care and help them thrive," he told crowds.
"In Sesotho, the language of the Basotho - the word Sentebale means 'forget-me-not'.
"Next week is the 25th anniversary of my mother's death, and she most certainly will never be forgotten.
"I want it to be a day to share the spirit of my mum with my family, with my children, who I wish could have met her."
Diana was a fervent campaigner against the stigmatisation of HIV and AIDS, famously shaking the hands of patients in the 1990s when many still believed the virus could be passed on by physical contact.
Harry and William support causes close to their mother
Having taken on the cause of HIV/AIDS as a tribute to her, he has publicly been tested for the virus several times, most notably in 2016 alongside singer Rihanna.
His brother Prince William has also devoted himself to issues close to Diana's heart.
To mark his 40th birthday in June this year, he joined Big Issue sellers in London and worked with the homelessness charity The Passage.
He said at the time on Twitter: "I was 11 when I first visited @passagecharity with my mother and since then, homelessness has stuck with me as an issue I want to fight for.
"I have always believed in using my platform to help bring attention and action to those who are struggling and I commit to doing what I can to shine a spotlight on this solvable issue not just today, but in the months and years to come."