Donald Trump to Hillary Clinton: I'll release my tax returns if you publish your deleted emails

HEMPSTEAD, NY - SEPTEMBER 26: Republican presidential nominee Donald Trump (R) debates Democratic presidential nominee Hillary Clinton as Moderator Lester Holt (C) looks on during the Presidential Debate at Hofstra University on September 26, 2016 in Hempstead, New York. The first of four debates for the 2016 Election, three Presidential and one Vice Presidential, is moderated by NBC's Lester Holt. (Photo by Joe Raedle/Getty Images)

Credit: Tamar Hallerman

Credit: Tamar Hallerman

HEMPSTEAD, NY - SEPTEMBER 26: Republican presidential nominee Donald Trump (R) debates Democratic presidential nominee Hillary Clinton as Moderator Lester Holt (C) looks on during the Presidential Debate at Hofstra University on September 26, 2016 in Hempstead, New York. The first of four debates for the 2016 Election, three Presidential and one Vice Presidential, is moderated by NBC's Lester Holt. (Photo by Joe Raedle/Getty Images)

Republican presidential candidate Donald Trump said he would release his tax returns if Democrat Hillary Clinton publishes the more than 30,000 emails that were deleted from her private email server when she was secretary of state.

Trump so far has refused to release his returns -- a break from decades of precedent -- because of an audit. But Trump said he would go against the advice of his lawyers if Clinton acts first.

"My lawyers they say don't do it ... I would go against them if she releases her emails," said Trump, drawing cheers from the audience, which was supposed to stay silent during the debate.

Clinton said she made a "mistake" using the private email server as secretary of state. "I take responsibility for that," she said, before refocusing on Trump's taxes.

"It just seems to me that this is something that the American people deserve to see," she said. "And I have no reason to believe that he's ever going to release his tax returns because there's something he's hiding. We'll keep guessing what it might be that he's hiding."

Complete debate coverage