EU Commission chief Jean-Claude Juncker has warned of an alarming lack of progress in talks on Greece's bailout, as Germany raised the spectre of a Greek exit from the euro.
Juncker was on Friday meeting with Alexis Tsipras, the leader of the hard-left Syriza party who came to power in January, just days after Tsipras renewed a demand that powerful Germany repay debts from its Nazi past.
"I am not satisfied by the developments in the recent weeks," Juncker said before talks began with Greece's 40-year-old premier.
"I don't think we have made sufficient progress, but we will try to push in the direction of a successful conclusion of the issues we have to deal with."
Greece won a four-month extension of its EU-ECB-IMF bailout in February - despite Tsipras initially saying he wanted to abandon austerity and have a completely new arrangement - but it will not get any of the cash until new reforms are approved by its eurozone partners.
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But frustrations in the eurozone with the Greek government are mounting after Athens this week renewed the claim to Germany for World War II debts seen as outlandish by its partners.
Greece's harshest critic German Finance Minister Wolfgang Schaeuble warned that with all the time wasted, a disorderly "Grexident" that could push Athens out of the euro could not be excluded.
"To the extent that Greece is solely responsible and decides what is to happen, and we don't know exactly what Greek leaders are doing, we can't exclude it," Schaeuble told Austrian broadcaster ORF.
A German finance ministry spokeswoman later rowed back on Schaeuble's comments, stressing that "we do not want Greece to leave".
Juncker however insisted after his meeting with Tsipras that failure was not an option, and pleaded for a breakthrough.
"I am totally excluding a failure, I don't want a failure. I would like Europeans to go together," the former Luxembourg premier said.
The two agreed that former Latvian premier Valdis Dombrovskis, the European Commission vice-president for the euro, would lead a "task force" that would deal with Greek officials for further talks.
Athens faces an urgent cash crunch, having to find 6.0 billion euros ($A8.31 billion) in the next two weeks alone to pay its creditors.
