Greek conservative New Democracy (ND) party leader Antonis Samaras said on Monday that he failed to form a national government of the debt-laden country, handing the task to the leftist Syriza party.

Samaras, as chief of the party that ranked first with about 19 percent of votes, had received the exploratory mandate from President Karolos Papoulias earlier on Monday afternoon.

He held a round of separate talks with all leaders of the parties that enter the new parliament with the exception of the neo-fascist Cryssi Avgi (Golden Dawn), seeking common ground for the formation of a national unity government that ended up fruitless.

"We did everything possible, but it was not feasible... I formally informed the President over the handing back of the mandate," he said in a statement.

Samaras had called for the formation of a national salvation administration with two goals -- to keep Greece within the eurozone and amend the recession-fuelling austerity aspect of the bailout agreements signed with European Union and International Monetary Fund creditors over the past two years to avert a Greek chaotic default.

However, deliberations collapsed quickly over "diametrical differences" regarding the composition of such a government and its policies.

Meanwhile, leftist Syriza coalition leader Alexis Tsipras, as head of the party which came second in the polls, leading the anti-bailout block, is expected to receive the mandate from the president on Tuesday and try to form a "progressive anti-austerity coalition."

If he could not manage to form a national government over the next three days, according to the Greek Constitution, the third party gains the opportunity and if it also fails, the country would head to a second round of elections, most likely mid-June, said local media commentators.