Prince Harry will address delegates at an Aids conference today as he takes his campaign to raise awareness about HIV to the international stage.
Harry will share a platform at Aids 2016 with Sir Elton John, a prominent campaigner. After the two men have delivered speeches they will host a youth-focused discussion at the event being staged in Durban, South Africa.
The joint session will address the HIV epidemic among adolescents with an emphasis on the impact stigma and discrimination have on young people.
Sir Elton and Harry will be joined by a panel of young advocates who will describe what is, and what is not, working for the HIV response among young people, and what must change to address the needs of youth with HIV.
Harry's charity Sentebale already focuses on supporting HIV positive young people in the African nation of Lesotho, but the Prince now aims to spread the message to his generation that the fight against HIV/Aids has not yet been won, Kensington Palace has said.
Sir Elton, who established a foundation to help in the global fight against Aids, said: "Today, HIV/Aids is a treatable disease and no longer the death sentence it was 10 years ago, but we cannot grow complacent in our fight to eradicate it completely.
"If our efforts wane, anti-viral drug resistance will resurface, transmission rates will again rise, and this disease, which knows no boundaries, will once again become a ruthless pandemic with disastrous and far-reaching consequences."
Harry underwent a public test for HIV last week and admitted to feeling nervous before the finger-prick procedure was carried out and produced a negative result.
When it was announced some weeks ago the Prince was to focus part of his public work on highlighting the fight against Aids, the move was welcomed by HIV charities and organisations who said his involvement with the issue would help shine a spotlight on the "epidemic" of people contracting the virus.
The latest data from Public Health England shows in 2014 there were an estimated 103,700 people living with the disease in the UK, with 17% of these not aware of their HIV infection.
In 2014 almost 85,500 people were accessing HIV treatment and care, more than double the number (41,157) in 2004, and a 5% increase on 2013.