The European Central Bank said Sunday it would keep its emergency cash lifeline to debt-hit Greece at current levels, while closely monitoring financial markets and "the potential implications for the monetary policy stance".

"The Governing Council decided to maintain the ceiling to the provision of emergency liquidity assistance (ELA) to Greek banks at the level decided on Friday," it said after a telephone conference.

Bank of Greece chief Yannis Stournaras said in the same statement that his bank "will take all measures necessary to ensure financial stability for Greek citizens in these difficult circumstances".