Greek PM Alexis Tsipras has held intense talks with international creditors in efforts to find a solution to Greece’s debt crisis.
Mr Tsipras has criticised lenders for rejecting his latest reform proposals, which they say are not viable.
Late night talks with the European Commission, the European Central Bank (ECB) and the International Monetary Fund (IMF) ended without agreement.
Greece must pay the IMF €1.6bn (£1.1bn) within days or face default.
Talks in Brussels between Mr Tsipras and Greece’s creditors are expected to resume at 09:00 (07:00 GMT) ahead of a Eurogroup meeting of eurozone finance ministers scheduled for 13:00 (11:00 GMT).
They hope to cut a deal that would release further loans to Greece before it runs out of money.
On Wednesday, finance ministers cut short a meeting that had been meant to finalise a deal.
Mr Tsipras held several hours of talks but officials said there was little sign of a breakthrough, with differences over whether the reform plan should have an emphasis on tax rises or pension and spending cuts.
The negotiations reconvened in the evening but again ended without a deal.
The Greek government may think it has given significant ground in its latest proposal. The creditors appear to be saying think again.
So the mood goes from bad to good and back again. In terms of absolute numbers, the distance between the two sides isn’t huge. But the political gulf is significant.
And Greek Prime Minister Alexis Tsipras is caught between a rock and a hard place – between the promises he made to his voters back home, and the commitments the creditors insist he must respect.
But these negotiations aren’t just about budget targets. The Greeks are also demanding that there has to be serious discussion of debt restructuring.
On that issue there is more sympathy from the IMF. But there is less from the European Central Bank and several eurozone countries.
Only once agreement is reached will creditors unlock the final €7.2bn tranche of bailout funds.
The latest Greek proposals are believed to include:
New taxes on businesses and the wealthy
Selective increases in VAT
Savings in pensions linked to curbing early retirement and increasing pension contributions
No further reductions in pensions or public-sector wages – “red lines” for Greece’s Syriza government.
But German Finance Minister Wolfgang Schaeuble said a deal was not close.
“I get the impression that we haven’t come much further than we were on Monday,” he said.
“But we are just beginning, then we will see. In any case, the preparations that were made do not make one optimistic that we will find a solution today. ”
Tight schedule – the week ahead
Thursday-Friday: Finance ministers to put finishing touches to a debt deal if reached; then scheduled meeting of all 28 EU member states – any agreement could receive leaders’ backing here
Saturday-Tuesday: Agreement will need to be approved by Greek parliament and other eurozone governments – including vote in German Bundestag
Tuesday 30 June: Deadline for Greek repayment of €1.6bn to IMF
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The Greek government has put forward budget proposals that it says meet the targets demanded by its creditors.
But the BBC’s Chris Morris in Brussels says they include far more tax rises and far fewer spending cuts than its creditors had suggested, and the IMF in particular is refusing to accept them.
This prompted Mr Tsipras to tweet: “The repeated rejection of equivalent measures by certain institutions never occurred before – neither in Ireland nor Portugal.
“This odd stance seems to indicate that either there is no interest in an agreement or that special interests are being backed.”
Our correspondent says he appears to be alluding to fears that there are those elsewhere in the eurozone who want to put the Greek prime minister in an impossible position, and engineer the collapse of his radical left-wing government.
However, IMF director Christine Lagarde said that the Greek government’s tax plans were not viable.
“You can’t build a programme just on the promise of improved tax collection, as we have heard for the past five years with very little result,” she said in an interview for the French magazine Challenges (in French).
“Creditors are expecting credible, tangible measures which will allow the budgetary situation to be redressed.”
There are also reports that Greece has rejected an IMF counter-proposal calling for bigger VAT increases, and deeper pension and public spending cuts.
Finance Minister Yanis Varoufakis’s spokesman Dimitris Yannopoulos tweeted: “IMF stance has changed: Now says GR debt sustainable if pensions (& wages) squeezed to unsustainably low levels. Shock Doctrine”
If agreement is reached, it will have to be endorsed by Greece’s parliament, with some critics at home accusing the left-wing prime minister of reneging on his party’s campaign pledge to end austerity.