Greek Prime Minister Alexis Tspiras has "torn down the bridges" between Greece and Europe and new negotiations are "difficult to imagine" after the apparent 'No' vote in the Greek referendum, German deputy chancellor Sigmar Gabriel said on Sunday.

Tsipras and his government are taking Greece down a path of "bitter renunciation and hopelessness," Gabriel told the Tagesspiegel newspaper in the first high-level reaction from the German government.

Tsirpas has "torn down the last bridges which Europe and Greece could have crossed to find a compromise," Gabriel said. "By saying 'No' to the eurozone's rules ... negotiations over billions of euros in bailout programmes are difficult to imagine."