WASHINGTON (REUTERS) - United States President Joe Biden and First Lady Jill Biden reported a drop in their federal income to US$607,336 (S$810,976) in 2020 from US$985,223 in 2019, when they earned money from book sales and speeches, according to their tax returns, which the White House released on Monday (May 17).

The Bidens paid US$157,414 in federal income tax and their 2020 effective federal income tax rate is 25.9 per cent, the White House said in a statement.

The Bidens also reported holding cash and investments between US$1.2 million and US$2.88 million in a financial disclosure filed with the Office of Government Ethics.

The release of Mr Biden's taxes is a return to normal practice by modern US presidents. Former President Donald Trump repeatedly refused to release his tax returns, claiming multiple times that he was not able to as he was being audited by the Internal Revenue Service, even as the agency claimed he was free to do so.

"With this release, the President has shared a total of 23 years of tax returns with the American public," the White House said.

The White House also released 2020 tax returns for Vice-President Kamala Harris and second gentleman Doug Emhoff. They reported a combined income of US$1,695,225, most of which came from Mr Emhoff's work at a law firm. They paid US$621,893 in federal income tax at a rate of 36.7 per cent.