Greece cannot service its huge debt and will seek a bridge loan rather than an extension of its bailout, Prime Minister Alexis Tsipras has said.
In an address to parliament, he also promised measures to cut bureaucratic spending and said his government would stick to all its pre-election pledges.
Mr Tsipras’s far-left Syriza party won elections last month on a promise to end austerity measures.
EU officials have rejected his efforts to renegotiate Greece’s bailout terms.
Greece’s current programme of loans ends on 28 February. A final €7.2bn (£5.4) is still to be negotiated.
“The bailout failed,” Mr Tsipras told parliament on Sunday. “The new government is not justified in asking for an extension… because it cannot ask for an extension of mistakes.”
He said that Greece wanted to service its debt. “If our peers want so, too, they are invited to come to the table of dialogue so we can discuss how to make it viable,” he added.
Demonstration in Athens, 6 February 2015 Greeks demonstrated in Athens this week in support of the new government’s stance
Greece wants permission to issue additional short-term debt while it seeks a new deal.
Mr Tsipras and his finance minister went on a diplomatic tour this week to try to reassure eurozone leaders about their plans.
However, Jeroen Dijsselbloem, who chairs the Eurogroup made up of eurozone finance ministers, said on Friday that Greece had to apply for a bailout extension if it wanted continued backing from the eurozone. “We don’t do bridging loans,” he said.
The European Central Bank has also issued a statement saying Greek banks could no longer access ECB credit by using Greek government bonds or bonds guaranteed by the government.
In last month’s elections Syriza fell just short of an outright majority and formed a coalition government with the centre-right Independent Greeks.
On Sunday, Mr Tsipras said the government’s “irreversible decision is to implement in full our pre-elections pledges”.
The first priority, he said, was “tackling the big wounds of the bailout, tackling the humanitarian crisis”.
That included giving free food and electricity to those worst affected by the economic crisis, and ending an unpopular annual levy on private property.
Among other commitments outlined on Sunday were:
a gradual rise in the minimum wage to €751 by 2016
reinstatement of public sector employees “fired illegally”
the creation of a new national broadcaster.
Two of the measures – raising the minimum wage and restoring a tax-free threshold to €12,000 – contravene reforms made previously as conditions for receiving bailout money.
Mr Tsipras also announced a number of measures aimed at cutting costs or raising revenue, including
a new tax on large properties
a special portfolio to oversee fight against corruption and tax evasion
a pension fund using revenues from natural resources
cutting ministry cars and government aeroplanes.
The Greek prime minister also repeated demands that Germany pay reparations for World War Two and repay a loan that the Nazis forced the Bank of Greece to pay when they occupied Greece.
Greece had “a moral obligation to our people, to history, to all European peoples who fought and gave their blood against Nazism,” he said.
Greek debt stands at more than €320bn, or about 174% of Greece’s economic output.
Eurozone finance ministers are due to meet on 11 February to discuss Greece’s debt proposals.