Greek Prime Minister Alexis Tsipras said in a speech in Berlin to a congress of European leftist parties on Saturday that it was time for his country's creditors to understand that the Greek people have made enough sacrifices.

Tsipras also said that Greece would not surrender to those who want Greece to permanently maintain austerity policies.

"Our creditors need to keep in mind that the Greek people have made enough sacrifices and now it's time for them to fulfill their obligations," he said. "We are decisive that we will never surrender our people to the 'yes men' who want Greece in the straight jacket of austerity for many years ahead."

"We have delivered on our obligations and our creditors need to do their part," he said. "I'm optimistic that Greece will achieve its goals. But we will never accept the logic of 'eternal austerity' that destroys Greek society." [Reuters]