Elton has posted a photo of himself with Princess Diana, adding that twenty years ago, ''the world lost an angel.''
He has said about performing Candle in The Wind 1997 at his friend's funeral: "What was going through my mind was 'Don't sing a wrong note. Be stoic. Don't break down and just do it to the best you can possibly do it without showing any emotion whatsoever.'
"My heart was beating quite a lot, I have to say."
Her son has since revealed that listening to Elton doing the song was ''like someone firing an arrow'' through his emotional defences.
Prince Harry also said he was determined not to cry in public but the song brought him to the brink.
Meanwhile, the Elton John AIDS Foundation has acknowledged ''the outstanding contribution that Princess Diana made to the fight against AIDS, helping keep men like Gerard McGrath alive. This year, Prince Harry, who carries on Diana's work in the fight against AIDS, met Gerard with Elton John when they visited London Lighthouse, the place where Diana had met Gerard 28 years ago.''
The pop legend has also been thinking about his forthcoming film.
On his Instagram page, there's a photo of the Kingsman: The Golden Circle cast, which includes the vocalist.
Alongside this he has written: ''I'll see you in London on September 18th for the world premiere!''
The world premiere will take place at the Odeon Leicester Square and in the IMAX screen at Cineworld Leicester Square. The filmmakers and cast will introduce both screenings.