The ECB will need to widen its monetary policy toolkit to ensure it remains effective, the European Central Bank's Vice President Luis De Guindos said.

In his view, the "toolkit will need to be wider" in the sense that the central bank needs to do more than conventional monetary policy, De Guindos said at BNP Paribas banking conference.

The ECB is in the process of reviewing its monetary policy and the tools it uses to keep inflation near 2% and support the euro zone economy.

In September, the bank pushed euro zone interest rates further into negative territory and said it was restarting its mass bond-buying programme having only wound it down at the end of last year.

It came with no end date in an attempt to reverse the slowdown in the euro zone's economy, nearly a decade after the bloc's debt crisis ripped through Greece, Italy, Spain, Portugal and Ireland.