PENSIONS CUT NEGOTIABLE

Juncker said he had made clear to Tsipras last week that items to which Greece objected, such as a demand to scrap an income supplement for the poorest pensioners, were open to negotiation if Athens put forward alternatives that yielded equivalent savings.

"He didn't tell parliament that we did address that subject already," the EU chief fumed.

There was no immediate reaction from Tsipras' office to the EU leaders' criticism, but Finance Minister Yanis Varoufakis continued the broadside against Greece's creditors in a blog post on Sunday.

"Greater austerity is being demanded from an economy that is on its knees, owing to the heftiest dose of austerity any country has ever had to endure in peacetime," he wrote.

"No offer of debt relief. No plan for boosting investment. And certainly, as of yet, no 'Speech of Hope' for this fallen people," Varoufakis said.

He urged German Chancellor Angela Merkel to address Greeks to signal Europe was ready to end its demands for austerity, just as US Secretary of State James F. Byrnes had given hope to Germans in a celebrated 1946 speech after World War Two.

Opinion polls show three-quarters of Greeks want to stay in the euro zone and a majority want the government to reach a deal with the lenders even if that means more sacrifices.

Juncker said he continued to rule out a Greek exit from the single currency but cautioned that that did not mean he could "pull a rabbit out of a hat" to prevent it if Greece was not willing to make an effort.

Juncker is widely seen as the senior EU official most sympathetic to Greece, and his display of anger showed how far Athens has gone in alienating its few allies in the bloc.

Among hardliners in the euro zone, Slovakian Finance Minister Peter Kazimir said the Greek government had won elections by promising things it could not deliver.

"The euro zone countries are trying to keep them in the euro zone but not at any cost," he said. "They have to surrender, to continue with the programme."