At an event in Chicago on Wednesday, Dimon said, "I don't know if [Warren] fully understands the global banking system," according to Bloomberg.
Dimon did add, however, that he agrees with some of Warren on the "risk side," and that he would be willing to meet with her in Washington anytime she wants.
Warren, the Democratic Senator from Massachusetts, has been one of the most vocal critics of banks and the financial system and has been chided, among other folks, Warren Buffett who said she should be "less angry and demonizing."
Recently, Warren made waves when she sent a letter to SEC chair Mary Jo White that many felt went too far, with Warren writing that she was, "disappointed that [White has] not been the strong leader that many hoped for."
Warren and Dimon also have history, with Warren writing in her book "A Fighting Chance" that Dimon once dared her to hit his bank with a fine.