“I don’t know if she fully understands the global banking system,” Dimon, speaking Wednesday at an event in Chicago, said of the Massachusetts Democrat. Still, he said he agrees with some of her concerns about risks.

Warren, a Senate Banking Committee member, has won popular support and gained influence in her party by openly challenging the size of large lenders and their political power. She has said it was a mistake for the U.S. government to refrain from breaking up big banks, such as Citigroup Inc., after the 2008 financial crisis.

Last month, as firms including JPMorgan pleaded guilty to resolve probes into market-rigging, she criticized regulators for granting waivers that let the companies continue operating certain businesses.

Dimon, who runs the largest U.S. bank by assets, said he would meet with Warren any time she wants. Warren’s office didn’t immediately respond to phone and e-mail messages seeking comment.

Past Meeting

A former law professor, Warren led the congressional oversight panel for the Treasury Department’s 2008 bailout of the financial system. She proposed the creation of what eventually became the Consumer Financial Protection Bureau to help shield Americans from predatory financial products after the crisis.

Dimon, 59, said he met with Warren during the agency’s founding to discuss credit cards. At the time, she said, “by the way I have your credit card, and I love it,” the CEO recalled Wednesday.

Later, when asked about his biggest worries, Dimon expressed concern that the U.S. eventually may be hurt by ideological decisions made in Washington. While he said he won’t run for office, he repeatedly returned to politics in his remarks, calling for immigration and tax reform and improvements to inner-city education.

Greek Strategy

On Greece, he said Prime Minister Alexis Tsipras is “playing a game,” betting other euro-zone members must cede to demands or watch their shared currency unravel. Dimon disagreed with that prediction.

If Greece exits the currency, there will “be huge volatility in the markets, fear, panic, op-eds,” but the remaining nations will “pull together quickly,” he said. “Europe will be better off for it.” And whether Greece exits by defaulting on debts or coming up with its own currency, “it will be really bad for the Greeks.”

Warren’s tactics have been a growing topic of debate in the U.S. this year. Last month, President Barack Obama accused her and other fellow Democrats who opposed his trade agenda of playing politics and misleading the public.

Billionaire Warren Buffett, who profited from investing in banks while faulting the industry’s lapses, said in March that her approach to Wall Street is too confrontational.

“She would do better if she was less angry and demonized less,” Buffett, who leads Berkshire Hathaway Inc., told CNBC at the time. “I believe in ‘hate the sin, and love the sinner.’”