Natalie DiBlasio

USA TODAY

Warren Buffett wants to make Donald Trump an offer "he can't refuse."

Trump can pick "any place, any time between now and election," and Omaha billionaire Buffett will bring his tax returns — if Trump does too." I'll bring my tax return. He can bring his tax return ... Just let people ask us questions about the items that are on there."

Every major party nominee since the late 1970s has released tax returns before Election Day, but Trump, so far, has not.

"You don't learn much from tax returns," Trump said in May. "But I would love to give the tax returns. But I can't do it until I'm finished with the audit."

Buffett countered, saying an audit is no excuse.

"Now I've got news for him, I'm under audit too," Buffett said of Trump's top defense of why he can't release the records. "There are no rules against showing your tax returns."

"You will learn a whole lot more about Donald Trump if he releases his income tax return," Buffett then said to the crowd as he introduced nominee Hillary Clinton at her Omaha event. He then asked Trump, quoting comments directed at Senator Joe McCarthy during the Army–McCarthy hearings, "have you no sense of decency, sir?