Bankers should let financial regulations play out before decrying their effect on markets, former Massachusetts Rep. Barney Frank said on Thursday.
Frank, a co-author of the regulatory Dodd-Frank Act passed after the 2008 financial crisis, was responding to recent assertions that safeguards have reduced liquidity in some markets, including Treasurys. Frank contended that perceived problems always surface under new systems.
"I believe the market is flexible enough to work that out, even with the rules," he said in a CNBC "Closing Bell" interview.
Read MoreSummers agrees with Dimon: There's a liquidity problem
Former Treasury Secretary Larry Summers and JPMorgan CEO Jamie Dimon in recent days warned about problems created by volatility in currency and Treasury markets. In his annual letter to shareholders on Wednesday, Dimon said that another economic crisis is inevitable.
Dimon also defended JPMorgan's size, contending that "larger does not necessarily mean more risky." Frank noted that he has not criticized JPMorgan's size in the past.
Read MoreDimon: Another crisis is inevitable
He also responded to former Hewlett-Packard executive and potential 2016 Republican presidential candidate Carly Fiorina, who on Thursday said she would urge repeal of Dodd-Frank if she became president. Frank said the call to abolish regulations will be "forced" on Republican candidates.
"I'm ready to debate that in 2016," he said.