Villeroy, who is also governor of the Bank of France, said that neither the ECB's determination nor its means to act should be called into question.

"On the means, we are in no way short of ammunition ... if necessary," Villeroy told lawmakers on the finance commission of France's lower house of parliament.

He cited in particular the level of interest rates, forward guidance about rates, the central bank's stock of assets and measures to boost banks' liquidity.