Greece's new finance minister has urged Germany to help end the "gross indignity" of the Greek debt crisis.
Yanis Varoufakis said "too much time, hopes, lives" had been wasted by Greece's forced austerity programme.
He was speaking after talks with his German counterpart, Wolfgang Schaeuble, who said a reduction of Greece's debt was off the agenda.
Mr Varoufakis has been seeking support for Greece's plan to renegotiate its massive international bailout.
On Thursday evening, thousands of people gathered in front of the Greek parliament to back the radical leftist Syriza party, which won last month's general election with a pledge to write off half the country's debt.
"It's the first demonstration in favour of a Greek government," Telemaque Papatheodorou, an engineer attending the rally, told the AFP news agency.
The demonstrators were also protesting against what they described as "blackmail" by the EU. Earlier on Thursday, the Greek stock market fell sharply after the European Central Bank (ECB) said it would refuse to accept Greek bonds in return for lending.
The ECB's move, a response to Greece's efforts to rewrite the aid-for-reform terms of its €240bn bailout, will force the Greek central bank to provide tens of billions of euros more emergency liquidity to the country's banks.
Greece's finance ministry played down the move, saying the country's banking system remained fully protected by alternative sources of funding.
Speaking after the meeting with Mr Varoufakis, Mr Schaeuble was quick to rule out a so-called "haircut" of Greece's debt, which stands at more than €320bn (£240bn; $366bn).
He said that Greece "belonged in the euro" and that Germany had offered to help the country meet its debt conditions by strengthening its tax system.
But he added: "I also could not conceal my scepticism that some of the measures the new government announced ... don't necessarily go in the right direction in our view."
Germany is seen as the strongest opponent among eurozone countries to the Greek government's plans to renegotiate the terms of the bailout.
Mr Schaeuble said he and Mr Varoufakis had "agreed to disagree" over the issue but had "come much further than anyone expected" in their talks.
Mr Varoufakis told the news conference that the two ministers had not got that far.
"As Mr Schaeuble said, we didn't reach an agreement. It was never on the cards. We didn't even agree to disagree, from where I'm standing."
'Largest loan in history'
On Thursday, the Greek finance minister said the conditions of austerity attached to Greece's 240bn euro (£179bn; $270bn) bailout had been "begetting indignity in my nation for too long".
Greek economy in numbers
- Unemployment is at 25%, with youth unemployment almost 50%
- Economy has shrunk by 25% since the start of the eurozone crisis
- Country's debt is around €321bn - 175% of GDP
- Borrowed €240bn (£188bn) from the EU, the ECB and the IMF
Mr Varoufakis said that the bailout provided in response was far too high, and called for more time to address the problem of Greece's debt.
"The largest loan in history was granted to the most insolvent of EU nations... With a list of reforms that was just a fig leaf," he said.
"This could not end well."
Earlier on Thursday, Mr Varoufakis compared Greece's plight to that of inter-war Germany.
Germany was burdened with massive debts after World War One and threatened by hyper-inflation, crippling the German economy and contributing to the rise of the Nazis.
In an interview with German ARD television, Mr Varoufakis said: "If you humiliate a proud nation for too long and subject it to the worry of a debt deflation crisis, without light at the end of a tunnel then things come to the boil."
He also warned about the rise of Greece's far-right Golden Dawn party, which came third in January's elections.
"It is one of history's greatest ironies that Nazism is rearing its ugly head in Greece."
Among those being sworn in to the new Greek parliament on Thursday were 17 members of Golden Dawn, including a number who were released from custody for the ceremony.
It came a day after 72 people with links to Golden Dawn - including its leader Nikos Michaloliakos - were indicted on charges including murder.
Correction 9 February 2015: An earlier version of this story incorrectly stated that the average wage in Greece is €600 a month.