Greek Finance Minister Yanis Varoufakis warned Monday that EU leaders had a duty to avoid a historic "failure" and urged a swift accord in Greece's debt talks with its creditors.
"What we need is an agreement quickly," Varoufakis told a discussion in Berlin on Greece's future within the EU, after talks earlier in the day with his German counterpart and other politicians.
Varoufakis warned against failure to reach a debt deal, saying history would see it as "a failure of the political class of the European Union, me, Dr (Wolfgang) Schaeuble, Mrs Merkel, Alexis Tsipras."
"We have a historic duty not to allow this to happen," he said to applause.
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.
Varoufakis also called on German Chancellor Angela Merkel to deliver a "speech of hope" in Greece, similar to the landmark address by US Secretary of State James Byrnes in Stuttgart in 1946, which marked a post-war shift to a policy of German economic reconstruction.
He said a speech of hope for Greece could "simply mark a sea change, a break in the past five years".
"Who should deliver this speech of hope? Well I think it should be the German chancellor," he said to applause, adding it could be held in Athens or any other Greek city or village.
The speech and discussion on Greece's future in the EU was organised by the Hans-Boeckler Foundation, which is close to the DGB union confederation.