TEMPO.CO, Jakarta - Frustrated and angry eurozone leaders fearing for the future of their common currency gave the Greek prime minister a last-minute chance to finally come up with a viable proposal on how to save his country from financial ruin.

Overcoming their surprise when Alexis Tsipras failed to present them with a detailed reform blueprint, the leaders reluctantly agreed to a final summit on Sunday, July 12, 2015, saying the days leading up to it could give both sides an opportunity to stave off collapse of the struggling but defiant member nation.

Underlining the gravity of the challenge, European Union President Donald Tusk decided to summon 28 EU leaders to Brussels, because, for the bloc, it "is maybe the most critical moment in our history."

French President Francois Hollande insisted much was at stake. "It's not just the problem of Greece — it's the future of the European Union," Hollande said.

Highlighting the rising anger with Tsipras over months of foot-dragging and surprising negotiating twists, European Commission President Jean-Claude Juncker had a stark warning for Greece.

"We have a Grexit scenario, prepared in detail," Juncker said, apparently referring to the situation in which Greece would be forced out of the currency union.

Speaking to reporters late Tuesday, Tsipras made it clear he had gotten the message that there wasn't a moment to waste as deadlines for debt payments that Greece cannot afford draw near.

"The process will be swift, it will be speedy, it will begin in the next few hours with the aim of concluding until the end of the week at the latest," Tsipras said.

According to a joint statement of the leaders, Tsipras must set out Greece's proposals in detail for a reform agenda by Thursday, July 9, 2015. The country's international creditors will then assess the plan to prepare for another meeting of eurogroup finance ministers and ultimately Sunday's summit of the full EU.

AP