The head of the European Stability Mechanism (ESM), Klaus Regling, said on Thursday that a Greek exit from the Eurozone is possible if Greece does not fulfil the conditions of its third bailout programme.

"This threat as a possibility must always be there and is still there," he said.

Regling ruled out the debt "haircut", but noted that talks about debt relief in autumn are possible.

He also said that he expects the International Monetary Fund (IMF) to participate in the third Greek bailout programme.