Donald Trump parodies former Republican presidential candidate Mitt Romney, calling him "a choker." EUTERS/Jonathan Ernst Presumptive Republican presidential nominee Donald Trump backed down on Friday from the possibility of debating Bernie Sanders, the Vermont senator trailing Hillary Clinton for the Democratic nomination.

Trump released a statement on Friday saying that, since he clinched the Republican nomination this week, he didn't think that he should debate the "second-place" Sanders.

He said in the statement:

Based on the fact that the Democratic nominating process is totally rigged and Crooked Hillary Clinton and Deborah Wasserman Schultz will not allow Bernie Sanders to win, and now that I am the presumptive Republican nominee, it seems inappropriate that I would debate the second place finisher.

The possibility of a Trump-Sanders debate first came up earlier this week when Trump made a seemingly nonchalant, off-the-cuff remark during an appearance on late-night talk show "Jimmy Kimmel Live!"

He told Kimmel that he was prepared to face off against Sanders after Clinton turned down an invitation to debate her Democratic presidential rival before the June 7 California primary.

"Yes, I am — how much is he going to pay me?" quipped Trump.

"If we paid a nice sum for the charity, I would love to do that," he added.

Sanders seemed up for it. Minutes after Trump's statement on the show, Sanders tweeted, "Game on."

And the Sanders campaign released a statement on Friday saying that its candidate was ready for the debate.

"Our campaign and the Trump campaign have received two offers by broadcast television networks to host the Sanders-Trump debate that we suggested. Both offers include a major contribution to charity," the statement read.

It continued:

We are prepared to accept one of those offers and look forward to working with the Trump campaign to develop a time, place and format that is mutually agreeable. Given that the California primary is on June 7, it is imperative that this all comes together as soon as possible.

Trump acknowledged in his own statement that the debate would be an "easy payday" for charity, but still declined to participate.

His statement read:

The networks want to make a killing on these events and are not proving to be too generous to charitable causes, in this case, women's health issues. Therefore, as much as I want to debate Bernie Sanders — and it would be an easy payday — I will wait to debate the first place finisher in the Democratic Party, probably Crooked Hillary Clinton, or whoever it may be.

Sanders released another statement Friday after Trump's statement, saying he hoped Trump would change his mind about the debate.

The statement read:

In recent days, Donald Trump has said he wants to debate, he doesn't want to debate, he wants to debate and, now, he doesn't want to debate.

Given that there are several television networks prepared to carry this debate and donate funds to charity, I hope that he changes his mind once again and comes on board.

There is a reason why in virtually every national and statewide poll I am defeating Donald Trump, sometimes by very large margins and almost always by far larger margins than Secretary Clinton. There is a reason for that reality and the American people should be able to see it up front in a good debate and a clash of ideas.

Allan Smith contributed to this report.