Donald Trump said that he’d “love” to debate Vermont Sen. Bernie Sanders, however, it won’t be free for the Vermont senator. The presumptive GOP nominee said it might take at least $10 million for the debate to occur.

“I’d love to debate Bernie, actually, the problem with debating Bernie is he’s going to lose,” Trump said at press conference in Bismark, N.D. The prospect of debating Sanders originates with Hillary Clinton refusing to debate Sanders at a Fox News debate before the California primary. Sanders agreed to the debate, and Clinton had previously agreed to do another debate.

Wednesday night on Jimmy Fallon, Trump said, “If [Bernie] paid a sum toward charity I would love to [debate].” Sanders than tweeted out, “Game On. I look forward to debating Donald Trump in California before the June 7th primary.”

Trump on Thursday continued to say that Sanders would have to agree to donate money to charity to debate, he said this is because he is in “first place.”

“I’d say something over $10 million,” Trump replied when asked how much Sanders would have to pay. “I love debating,” Trump added.