Britain's Prince Harry will begin his five-day visit to Singapore and Australia on Sunday to hold charity events including one that supports children living in Africa.

In Singapore, Harry will stage the Sentebale Polo Cup in aid of his charity of the same name, and will later travel to Australia to launch the 2018 Invictus Games which will be hosted by Sydney.

The charity polo match has become an important annual fund-raising event for Sentebale, a charity which works with children in Lesotho and Botswana who are coming to terms with being HIV positive, have AIDS or have lost their parents to the disease.

"Since Sentebale was founded in 2006, the charity has reached thousands of children and young people in Lesotho, and latterly in Botswana, who have been struggling to come to terms with living with the HIV by addressing their mental health and wellbeing, Press Association, Cathy Ferrier, Sentebale's chief executive officer, said.

"It is our ambition to see a reduction in the number of new HIV infections and AIDS-related deaths amongst adolescents in southern Africa, by putting youth first and equipping them with skills and relevant wraparound support that they need to lead healthy, productive lives," she said.

A 2004 gap year trip to the landlocked African nation of Lesotho inspired the prince to set up his charity two years later with the country's Prince Seeiso, younger brother of King Letsie III.

In November 2015 Sentebale opened its 2 million pounds Mamohato Children's Centre in Lesotho to scale up its Mamohato camps, a residential project providing psychological, social and practical support to children struggling to cope with being HIV positive.

In Sydney on Wednesday, the prince will attend events to celebrate the city's hosting of the 2018 Invictus Games, the international sporting competition for wounded, injured and sick service personnel and veterans founded by the prince in 2014.

The Invictus Games, which this year will be held in Toronto, Canada, has been the other main long-term focus of Harry's public work, and he is patron of the Invictus Games Foundation, which oversees the delivery of the tournament.