President Donald Trump lashed out at JPMorgan Chase CEO Jamie Dimon, claiming the Wall Street executive is a "nervous mess" who lacks the "smarts" to be president.

Mr. Trump's assertion comes after Dimon remarked on Wednesday that he could beat President Trump in a presidential election, before backpedaling as his comments drew media attention. Dimon, who spoke at an event at his bank's New York headquarters, also asserted that he is "smarter" than Mr. Trump.

"I think I could beat Trump," Dimon said early Wednesday, according to media accounts. "I'm as tough as he is, I'm smarter than he is. I would be fine. He could punch me all he wants, it wouldn't work with me. I'd fight right back."

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Dimon also took aim at Mr. Trump's wealth, saying of himself: "This wealthy New Yorker actually earned his money. It wasn't a gift from daddy."

Dimon has been CEO of JPMorgan, the biggest U.S. bank, since 2005.

"The problem with banker Jamie Dimon running for President is that he doesn't have the aptitude or 'smarts' & is a poor public speaker & nervous mess," Mr. Trump fired back in a Thursday morning tweet.

The problem with banker Jamie Dimon running for President is that he doesn’t have the aptitude or “smarts” & is a poor public speaker & nervous mess - otherwise he is wonderful. I’ve made a lot of bankers, and others, look much smarter than they are with my great economic policy! — Donald J. Trump (@realDonaldTrump) September 13, 2018

Mr. Trump added that his economic policies are making "a lot of bankers, and others, look much smarter than they are."

Later on Wednesday after making those comments, Dimon denied any interest in running for president.

"I should not have said it," he said in a statement. "I'm not running for president. Proves I wouldn't make a good politician. I get frustrated because I want all sides to come together to help solve big problems."