Sir Elton John and Brandi Carlile are trying to make up the money lost by Donald Trump's cuts to HIV/AIDS funding

Through the music collaborator's respective charities, Elton John AIDS Foundation and the Looking Out Foundation, they are seeking donations to raise the money needed to make up the huge loss.

What's more, the Looking Out Foundation will match every donation up to $100,000 to "double the impact".

Elton, 78 - who just teamed up with Brandi on the joint album 'Who Believes in Angels?' - said: "Without prompt action, decades of progress in the global fight against HIV could be reversed, creating a global health crisis that we have both the power and the tools to prevent.

"Our mission is more important than ever - we refuse to leave anyone behind - and I'm so fortunate that Brandi is not only a wonderful collaborator and artist, but a dear friend who shares my vision of a world where HIV care is prioritised and protected."

Brandi, 43, commented: "It was a lifelong dream come true for me to come together with my hero and friend Elton John to make our album 'Who Believes in Angels?', and now, we're excited to announce that our foundations are also partnering to make our music mean even more."

She added: "Elton's activism and work with the Elton John AIDS Foundation was what led me to Elton before I even heard a note of his music. It's an incredible honor to launch this partnership and raise funds for the life-saving work of the Elton John AIDS Foundation and the Rocket Response Fund at a time when support is needed the most."

The Rocket Fund and Rocket Response Fund was launched to offset the cutbacks to the United States Agency for International Development (USAID), which is where the HIV/AIDS funding came from.

Since its launch in 1992, the Elton John AIDS Foundation has raised more than $500 million for life-saving treatment and advocacy.