Athens, Greece (BBN)-Greece has until the end of Thursday to present new proposals to secure a third bailout from creditors and prevent a possible exit from the eurozone.
Prime Minister Alexis Tsipras said the "next hours will be crucial".
The new proposals will be studied by eurozone finance ministers on Saturday and a full EU summit on Sunday, reports BBC.
The Greek government has meanwhile extended bank closures and the €60 (£43; $66) daily limit on cash machine withdrawals until Monday.
The curbs were imposed on 28 June, after a deadlock in bailout talks with creditors led a rush of withdrawals.
Louka Katseli, the head of the Greek bank association, said on Thursday that there was enough liquidity in cash machines to serve the public until Monday.
'VIABLE SOLUTION'
Tsipras returned to Athens on Wednesday night after meetings in Brussels and an address to the European Parliament.
He went straight into talks with other political parties. Tsipras said: "These are crucial times and it's necessary to provide proper information to the political parties so that there are no misunderstandings.
"I think we're proceeding within the framework of what was agreed and the next hours will be crucial."
CRISIS COUNTDOWN
THURSDAY 9 JULY: deadline for Greece to submit proposals
SATURDAY 11 JULY: eurozone finance ministers meet
SUNDAY 12 JULY: all 28 members of the European Union meet to decide Greece's fate
MONDAY 20 JULY: €3bn payment due from Greece to the European Central Bank
He has pledged to submit "new concrete proposals, credible reforms, for a fair and viable solution" by Thursday. However, the details are scant.
Greece has said it wants a major restructuring of its massive debt, and on Wednesday formally submitted a request for an unspecified loan from the European Stability Mechanism bailout fund.
This would be a fresh loan "to meet Greece's debt obligations and to ensure stability of the financial system", Greece says.
In return it has suggested it will implement new pension and tax measures from Monday.
French PM Manuel Valls said this was a step in the right direction.
And Christine Lagarde, managing director of the International Monetary Fund (IMF), one of Greece's creditors, on Wednesday admitted that "[restructuring] is needed in the case of Greece for it to have debt sustainability".
She said: "Greece is in a situation of acute crisis, which needs to be addressed seriously and promptly."
WHAT HAPPENS NEXT?
Greece's creditors - the European Commission, the European Central Bank and the IMF - have already provided more than €200bn in two bailouts since a rescue plan began five years ago.
The second bailout expired on 30 June.
The creditors had hoped for new, concrete proposals from Greece at a meeting on Monday but these were not submitted and they instead agreed to set a new deadline of Thursday.
Greece has been warned this is the "final deadline".
European Council President Donald Tusk said this was "now maybe the most critical moment in the history of the eurozone".
"This is really and truly the final wake-up call for Greece and for us, our last chance," he said, adding that failure "may lead to the bankruptcy of Greece".
On Wednesday, Tsipras, speaking during a fractious debate in the European Parliament, criticised previous bailouts for turning Greece into an "austerity laboratory".
He was speaking after the Greek people decisively rejected the latest proposals from creditors in a referendum on Sunday.
BBN/SK/AD