Hours before his first debate with President Donald Trump, Democratic presidential nominee Joe Biden on Tuesday released his 2019 tax returns and his campaign called on Trump, who has come under fire for not releasing his returns, to do the same.

Biden, due to share the stage with Trump on Tuesday evening in Cleveland, took the step two days after the New York Times reported that Trump paid just $750 in federal income taxes in 2016 and 2017 - and none in 10 of the previous 15 years - after reporting years of heavy losses from business enterprises.

Trump had long sought to keep his personal financial records secret.

Biden's taxes showed that he and his wife Jill paid more than $346,000 in federal taxes and other payments for 2019 on an income of nearly $985,000 before seeking a refund of nearly $47,000 they said they had overpaid the government.

"This is a historic level of transparency meant to give the American people faith once again that their leaders will look out for them and not their own bottom lines," Biden's deputy campaign manager, Kate Bedingfield, said on a call with reporters.

"Mr. President, release your tax returns or shut up," Bedingfield added.

With more than a million Americans already casting early ballots and time running out to change minds or influence the small sliver of undecided voters, the stakes are enormous as the two White House candidates take the stage five weeks before the Nov. 3 election.

The 90-minute debate, with a limited and socially distanced in-person audience because of the pandemic, will begin at 9 p.m. EDT (0100 GMT on Wednesday) at Case Western Reserve University in Cleveland. It is the first of three scheduled debates.

The Biden tax returns gambit ahead of the debate shows that the former vice president is seeking political advantage on an issue that could resonate with voters - a wealthy real estate developer-turned-politician who has, according to the New York Times report, often avoided paying federal income taxes.

Democrats have sought to portray Trump as a tax dodger. Trump's persistent refusal to release his taxes has been a departure from standard practice for presidential candidates.

The Trump campaign did not immediately respond to a request for comment on whether the president would release his 2019 taxes.

The Times also reported that Trump was currently embroiled in a decade-long Internal Revenue Service audit over a $72.9 million tax refund he claimed after declaring large losses. If the IRS rules against him, he could have to pay over $100 million, according to the newspaper.

The 2019 tax returns for Biden's running mate, Senator Kamala Harris, also were released.

Harris and her husband, lawyer Doug Emhoff, reported paying about $1.2 million in total federal taxes on $3.3 million of income for the year, according to the tax returns released on Tuesday. Vice President Mike Pence released a decade of returns before the 2016 election but no tax information since then.

AN ARRAY OF ISSUES

The combustible Trump and more low-key Biden will debate an array of urgent political challenges, including a coronavirus pandemic that has killed more than 200,000 people in the United States and thrown millions out of work, a brewing battle over Trump's nomination of conservative judge Amy Coney Barrett to the Supreme Court, and continued protests for racial justice.

Biden has held a consistent lead over Trump in national opinion polls, although surveys in the battleground states that will decide the election show a much closer contest.

"Voters have made up their mind about Donald Trump. They still aren't quite sure what to make of Joe Biden," said Republican strategist Alex Conant, an aide to Senator Marco Rubio during his 2016 presidential primary bid against Trump.

"If Biden goes in and demonstrates he is not scary to independents and is capable of doing the job, he will help himself significantly," Conant said.

White House aides have said Trump, 74, will aggressively challenge Biden's record on issues such as trade, energy and taxes and will be prepared to defend himself on his own taxes. Trump, who has repeatedly cast doubt on the integrity of the election, is likely to face questions about his refusal to commit to accepting the election results and a peaceful handover of power should he lose.

Biden, 77, is certain to press his criticism of Trump's response to the pandemic, and highlight Trump's efforts to eliminate the Affordable Care Act, the law known as Obamacare that has helped millions of Americans obtain health insurance.

The debate will be divided into six segments - the records of Trump and Biden, the U.S. Supreme Court, the coronavirus pandemic, the economy, election integrity and "race and violence" in U.S. cities.

Ahead of the debate, Democrats have demanded that moderator Chris Wallace of Fox News correct Trump when he makes false claims. But Wallace, whom Trump has called "nasty and obnoxious," said he would not perform a fact-checking function.