Responding to a question from Corriere della Sera whether Athens must continue to meet its financial obligations, Benoit Coeure, a member of the ECB's Executive Board, said: "Greece must continue to abide by the rules of the game."

Coeure also spelt out the benchmark of success that will determine the duration of government bond buying by the ECB, a programme that was announced last week.

"It will end only once we get a strong sense that inflation is converging towards 2 percent."

(Reporting By John O'Donnell Editing by Jeremy Gaunt)