Crisis-stricken Greece has entered a second week of political deadlock following repeated failures by party leaders to agree on a unity cabinet and avert new elections.
Talks led by President Karolos Papoulias are to resume late on May 14. Reports say chances of a breakthrough appear slim.
Greece's general elections on May 6 boosted antiausterity far-left and far-right parties and stripped mainstream parties, which back a draconian EU-IMF bailout package, of their parliamentary majority.
A small party, the Democratic Left, had been seen as the most likely candidate to forge a coalition between the two mainstream conservative and socialist parties, the New Democracy and Pasok.
Technically, all three parties could form a coalition, but they have been insisting that they need the support of the radical leftist Syriza party, which finished second in the May 6 poll after a hard-line antiausterity and anti-EU campaign.
Syriza leader Alexis Tsipras, who has repeatedly rejected any coalition with pro-austerity conservatives and socialists, reiterated his stance on May 13.
"We will take our responsibilities, and the biggest responsibility we have to the people is for the people not to lose their hope," Tsipras said.
"The biggest responsibility we have is not to appear that we are backtracking on what we said before the elections and what we do after the elections. And we won't."
Democratic Left leader Fotis Kouvelis has said that "no unity government can emerge" after Tsipras' rejecting the offer to join a coalition.
"The president told me that, unfortunately until now, there is no possibility of the formation of an ecumenical government, and he referred to the refusal by Syriza to participate in such an ecumenical government, or to even show tolerance toward one," Kouvelis said.
Greece is facing pressure from European leaders to adhere to agreements it has made for a $310 billion bailout package.
If the last-ditch attempt at forming a coalition fails on May 14, new elections must take place in June.
Opinion polls indicate that Syriza, which finished second on May 6, would win a repeat election due to its antibailout campaign.
Meanwhile, the influential German magazine "Der Spiegel" has called for debt-crippled Greece's departure from the eurozone.
Under a front-page headline "Acropolis, Adieu! Why Greece Must Leave the Euro," the magazine argues that Greece's euro exit may be the best option.
"Der Spiegel" writes: "The Greeks were never ripe for the currency union and they still are not today. The attempt to make the country sustainable through reforms has failed."
German Finance Minister Wolfgang Schaeuble was quoted on May 13 as saying he could not force Greece to remain within the currency bloc, although he hoped it would.
Germany, which has Europe's biggest national economy, has led the EU's campaign to compel Greece to implement austerity measures and reduce its staggering debt in order to strengthen the viability of the euro.
With reporting by AFP, AP, dpa, and Reuters