Prince Harry has urged people to get tested for HIV.

Prince Harry

Prince Harry

The 31-year-old royal was joined by Sir Elton John as he signed the United Nations Programme on HIV/AIDS' ProTest wall where he questioned why anyone wouldn't want to take the simple test.

A series of tweets on Kensington Palace's official Twitter account reads: "Prince Harry and Sir Elton John have just signed @UNAIDS ProTEST wall to support regular HIV testing #ProTESTHIV ...

"Prince Harry's message on the @UNAIDS #ProTESTHIV wall - 'Get tested! Why wouldn't you? Harry' (sic)"

The flame-haired royal and the 'Rocket Man' hitmaker are due to address the International AIDS Conference on Thursday (21.07.16) where they will talk about how the disease can affect young people.

Meanwhile, Elton previously praised Prince Harry for undergoing a HIV test and broadcasting it live to the world.

He wrote at the time: "In 1991, Princess Diana moved a mountain by addressing the stigma surrounding people living with HIV/AIDS. She showed the world we could safely wrap our arms around AIDS patients, by shaking hands with a patient without gloves. We've made huge strides since then in the treatment of the disease.

"People now live long, happy lives with HIV, when the virus is effectively managed with anti-retrovirals. Despite this amazing progress, most people today are still frightened and stigmatised at the notion of taking an HIV test. Today in London, Prince Harry gave that stigma a knock on the head by showing the world how easy and simple it is to take an HIV test. Bravo Prince Harry! Your mother would be so proud of you."