Business mogul Donald Trump pledged during Thursday's Republican presidential debate that he would release his tax returns.

But first, he explained, the IRS must finish an audit of them before he makes the forms public.

"Everybody" would agree with him that he can't release them, Trump insisted.

No, they wouldn't.

It's up to Trump whether he releases the taxes he filed. An audit may change how much he owes the government in the end, but it won't change what he and his lawyers submitted to the IRS. He could release those documents whenever he wants.

Michael Ciaglo/Pool via Getty Images Donald Trump said Thursday that he will release his tax returns after the IRS finishes an audit on them.

Trump has been under heavy pressure in recent days to open up his financial portfolio to scrutiny after Mitt Romney encouraged him to do so.

Trump, incredulous that Romney would make the charge, noted that the 2012 Republican presidential nominee only released his tax returns late in that campaign.

“Mitt Romney looked like a fool when he delayed and delayed and delayed and Harry Reid baited him so beautifully. And Mitt Romney didn’t file his return until Sept. 21, 2012,” Trump said.

Romney fired back at Trump on Twitter:

No legit reason @realDonaldTrump can't release returns while being audited, but if scared, release earlier returns no longer under audit. — Mitt Romney (@MittRomney) February 26, 2016

As for the audit, Trump declared it routine and said the IRS puts his returns under scrutiny most years.

Editor's note: Donald Trump is a serial liar, rampant xenophobe, racist, misogynist, birther and bully who has repeatedly pledged to ban all Muslims -- 1.6 billion members of an entire religion -- from entering the U.S.