The European Commission spokeswoman Mina Andreeva said on Thursday that a deal between Greece and its creditors could be reached by August 20.

"What President Juncker himself said yesterday in an interview remains valid that the negotiations with the Greek authorities are 'progressing in a satisfactory way', that he believes 'an agreement this month preferably before August 20 is possible' because, as you know, August 20 is the date for an important payment to the ECB," she said.

According to the German newspaper Bild, the German government doubts that a deal on a third bailout programme for Greece can be reached in August. The government believes that Greece will need another bridge loan.