US President Barack Obama weighed in Monday on the Greece crisis, telling Greeks they need to make tough choices to save their country from a default and possible messy euro exit.
Obama said after a meeting with fellow G7 leaders that there is a "sense of urgency in finding a path to resolve the situation".
But a resolution requires Athens to be "serious about making some important reforms not only to satisfy creditors but more importantly to create a platform whereby the Greek economy can start growing again and prosper".
"So the Greeks are going to have to follow through and make some tough political choices that will be good for the long term," added the US leader.
While pushing the Greeks to hold up their end of the deal, Obama also called for flexibility from its creditors.
"If both sides are showing a sufficient flexibility, then I think we can get this problem resolved, but it will require some tough decisions for all involved," he said.
Germany, the host of the G7 summit, also urged Greece to speed up talks on a loan deal with its international creditors.
"There's not much time left. We have to work very hard on this," German Chancellor Angela Merkel said at the close the summit.
France's President Francois Hollande also stressed the importance of securing a deal quickly.
The end of June "is the maximum deadline but nothing stops us from moving quicker, and I think that it's in Greece's interest that it speeds up, to remove uncertainties", he said.
Greece needs to unlock some 7.2 billion euros ($8 billion) in rescue funds in order to be able to repay 1.6 billion euros to the International Monetary Fund by June 30.
A default could trigger a series of events that could result in a messy exit from the euro.
But after five months the talks are still stuck on disagreement between Greece and its creditors on its future budget goals, economic reforms and tax revenues.
The radical-left government in Athens said it would continue efforts to reach agreement despite testy exchanges with European officials in recent days.
And Prime Minister Alexis Tsipras has sought a meeting on Wednesday with Merkel and Hollande on the sidelines of an EU-Latin America summit in Brussels.
"Talks are continuing in Brussels at a political level to examine the prospects of a common agreement," Greek government spokesman Gabriel Sakellaridis told reporters.
He added that Minister of State Nikos Pappas, one of Tsipras' closest advisors, had joined the technical mission for Monday's talks.
- Stop finger-pointing -
As negotiations dragged, tempers have flared on both sides.
EU Commission chief Jean-Claude Juncker criticised Tsipras over the weekend, accusing the Greek leader of misrepresenting reform proposals that the bloc had put to Athens.
Juncker also said Athens had failed to deliver a counter-proposal of reforms.
The EU's five-page list of proposed reforms, including sales tax hikes and cuts to civil servants' salaries and pensions had been put to Greece last week.
But Tsipras rejected them as "absurd" and wants a 47-page blueprint his government put forward this past week to serve as the basis for the talks.
Greece's Finance Minister Yanis Varoufakis termed the proposals "borderline insulting" over the weekend.
Varoufakis on Monday sought to calm nerves, saying it was time the finger-pointing in debt talks with its EU-IMF creditors stopped and that both sides come to an agreement.
"It is time to stop pointing fingers at one another and it is time that we do our job to bring to fruition months of efforts to come to an agreement," he said in Berlin after meeting German Finance Minister Wolfgang Schaeuble.
Tsipras, 40, is under pressure from hardliners in his radical left Syriza party to reject any deal that piles further austerity on the recession-hit country.
Several Syriza members have called for early elections if the government is forced to accept austerity measures outside its mandate.
"If we cannot bring this to a conclusion, I believe the people should be asked to give a mandate with certain new limits," Labour Minister Panos Skourletis told the Mega channel on Monday.