Mario Draghi defended negative rates in a speech to the legislative assembly in the Netherlands.
It was a rare trip to a national parliament by the president of the European Central Bank.
Along with their German counterparts, Dutch politicians have been the most vocal critics of the ECB’s monetary stimulus,
which, they say, helps profligate countries in the euro zone at the expense of banks and savers in more frugal ones.
A rally in Greek government debt continued, with the yield on the benchmark ten-year bond falling to 5.5%, the lowest since its debt restructuring in 2012.
The government recently agreed to a series of reforms in order to unlock the latest tranche of loans under the rescue package agreed with international creditors.
The European Bank for Reconstruction and Development flatly rejected a plea by Russia to end its freeze on investment in the country,
which was introduced as a result of the conflict in Ukraine in 2014.
The EBRD was created in 1991 to help post-Soviet countries make the transition to democracy.
Russia claims the ban on investment is affecting the whole economy and breaches EBRD rules.
Oil prices recouped some of their recent losses.
After falling by 6% in the space of a week to a five-month low, Brent crude rose to over $50 a barrel.
Prices were boosted in part by comments from the Russian and Saudi energy ministers about the possibility of extending a deal that cuts oil production.