Greece's new left-wing finance minister says his government will not negotiate over the Greek bailout conditions with the "troika" team from the EU and IMF.
Yanis Varoufakis said he was rather seeking direct talks with eurozone leaders, to try to cancel more than half the money Greece owes.
He was speaking after meeting Jeroen Dijsselbloem, head of the eurozone group of finance ministers, in Athens, the BBC reports.
Mr Dijsselbloem said Greece should stick to its reform commitments.
He said Greece and the Eurogroup had a "mutual interest in the further recovery of the Greek economy inside the eurozone" and warned against Athens acting unilaterally in its efforts to renegotiate its bailout.
Greece has endured tough budget cuts in return for its €240bn bailout, agreed in 2010 with the "troika" - the European Commission, International Monetary Fund (IMF) and European Central Bank (ECB).
In Berlin, German finance minister Wolfgang Schaeuble said the Greeks should abide by their commitments, adding: "There's no arguing with us about this and, what's more, we are difficult to blackmail."
There was little warmth between the two men at the news conference, with Mr Dijsselbloem making a brusque exit.
Breaking with tradition, Mr Varoufakis wore an open-neck shirt - hanging loose at his belt. Mr Dijsselbloem was dressed conventionally.
On the troika, Mr Varoufakis said, "we have no intention of co-operating with a three-member committee whose goal is to implement a programme whose logic we consider anti-European".
Mr Dijsselbloem, who is also Dutch finance minister, said the two sides would decide what would happen next before the bailout programme ends - that is, by 28 February.
He also met Greek Prime Minister Alexis Tsipras in Athens, who led the Syriza radical left-wing coalition to victory in elections on Sunday.
Mr Varoufakis, meanwhile, said Greece was not asking for an extension of the existing bailout, but seeking a "new agreement that will emerge following talks between all Europeans".
He said he would seek "maximum co-operation" with Greece's international creditors, but that he would not work through the troika, which he called "a committee built on rotten foundations".
Mr Dijsselbloem rejected Mr Tsipras's idea of convening a European conference on debt. "This conference already exists and it's called the Eurogroup," he said.