U.S. banks won't be rescued by taxpayers, U.S. Treasury Department official Mary Miller said, rebutting investor skepticism that some lenders are too large to be allowed to fail.

"A common use of the too-big-to-fail shorthand is the notion that the government will bail a company out if it is in danger of collapse because its failure would otherwise have too great a negative impact," Miller, the Treasury's undersecretary for domestic finance, said in remarks prepared for a speech in New York late yesterday. "With respect to this understanding of too-big-to-fail, let me be very clear: It is wrong."

A debate from Washington to Wall Street over whether the Dodd-Frank financial overhaul law ends bailouts was re-energized after U.S. Attorney General Eric Holder said last month that the size of the largest banks has made it difficult for the Justice Department to bring criminal charges when there is wrongdoing.