The leaders of Greece, France and Germany have agreed to intensify negotiations with Athens’ creditors, but there was little sign of progress.
After late night talks in Brussels, Greek Prime Minister Alexis Tsipras said all the sides would work to “bridge” remaining differences.
The EU and IMF want further economic reforms before they release €7.2bn (£5.3bn) of bailout funds to Athens.
Greece faces default at the end of June if it fails to repay €1.5bn to the IMF.
Earlier this week, Athens submitted a revised reform plan to the EU and IMF, after Mr Tsipras rejected a set of reforms put forward by EU Commission President Jean Claude Juncker.
It is believed Athens has conceded ground on VAT reforms, pensions and the country’s primary surplus target.
Mr Tsipras is expected to hold further talks with Mr Juncker later on Thursday.
“We decided to intensify efforts to resolve the differences that remain and to move towards a solution,” the Greek prime minister told reporters after his meeting with German Chancellor Angela Merkel and French President Francois Hollande.
“The European leaders realised that we must offer a viable solution and the chance for Greece to return to growth,” Mr Tsipras added.
Ms Merkel and Mr Hollande left the talks without making public comments, however a German government statement said the three leaders had agreed that the negotiations “must be intensified”.
The statement also said the meeting in Brussels was constructive.
In his comments, Mr Tsipras indicated he had stuck to his demand for some debt relief for Greece, the BBC’s Damian Grammaticas in Brussels reports.
But European leaders will not countenance writing off debts before Greece commits to reforms. So there appears to have been little achieved and only a few more days for all sides to find a solution, our correspondent adds.
Last week, Greece “bundled up” a €300m payment to the IMF, delaying the payment until the end of June when a total of €1.5bn is due to be paid.
Mr Tsipras has warned earlier that a failure to reach a deal on Greece’s bailout by the end of June would be the beginning of the end for the eurozone.