"The risks surrounding the economic outlook for the euro area remain on the downside," Draghi said at a news conference after the bank had left interest rates unchanged.

"In particular, geopolitical risks, as well as developments in emerging market economies and global financial markets may have the potential to affect economic conditions negatively, including through effects on energy prices and global demand for euro area products," he said.

He said this meant interest rates - currently at record lows of 0.15 percent - were not likely to move.

"The key ECB interest rates will remain at the present levels for an extended period of time in view of the current outlook for inflation.

"Moreover, the Governing Council is unanimous in its commitment to also using unconventional instruments within its mandate, should it become necessary to further address risks of too prolonged a period of low inflation."

(Reporting by Eva Taylor Editing by Jeremy Gaunt)