U.S. regulators are getting fed up with Wall Street's attempts to stall a restriction on risky swaps trades.

JPMorgan Chase & Co., Citigroup Inc., and other lenders have already won one delay of the measure that forces them to move derivatives out of units with federal backstops. Getting another reprieve is crucial for banks, because it would give them time to persuade a Republican-led Congress to kill the requirement.

"Just because it's authorized doesn't mean it happens," Comptroller of the Currency Thomas Curry said when asked whether Wall Street would get another extension, which regulators can grant under the Dodd-Frank Act. Banks should be ready to comply with a July deadline, he said in an interview.