European Central Bank head Mario Draghi is defending the current low level of interest rates against charges they hurt savers and favor the wealthy.

Draghi said in a speech in Berlin on Tuesday that low rates are a symptom of underlying weak investment and excess savings, which central banks must take into account. He said low rates support consumption and jobs — benefits that are "always socially progressive."

He said that, overall, "a faster return to full employment should in turn contribute to lower future inequality."

The ECB has cut its benchmark rate to zero, and pushed down longer-term rates through bond purchases. The steps have frustrated savers seeing low returns on conservative investments, while boosting stocks and other assets that are often held by more wealthy people.