Some of America's billionaires have a message for the next president of the United States: Tax us.

Nineteen billionaires and ultra millionaires including George Soros, Abigail Disney, Chris Hughes and members of the Pritzker family released a bipartisan letter on Monday asking the 2020 presidential candidates to support a tax on the American families with the largest fortunes.

"The next dollar of new tax revenue should come from the most financially fortunate, not from middle-income and lower-income Americans," the letter said. It was first reported by The New York Times.

A tax on America's wealthiest has been at the forefront of the 2020 election stage. Democratic presidential hopefuls Elizabeth Warren, Bernie Sanders, Pete Buttigieg, Beto O'Rourke and others have come out in support of a tax on the wealthiest Americans.

Earlier this year, Warren proposed a tax of 2% on wealth over $50 million and 3% on wealth over $1 billion. The proposal is estimated to generate nearly $3 trillion in tax revenue in the next decade.