Euro zone officials were shocked at Greece's failure to outline plans for structural reforms at last week's talks in Brussels, a German newspaper on Saturday cited participants as saying, adding the Greek representative behaved like a "taxi driver".

A meeting of deputy finance ministers on Thursday gave Athens a six working day deadline to present revised economic reform plans before euro zone finance ministers meet on April 24 to consider unlocking emergency funding to keep Greece afloat.

Euro zone sources told the Frankfurter Allgemeine Sonntagszeitung that they were disappointed and shocked at Athens' lack of movement in its plans, and in particular its reluctance to talk about cutting civil servants' pensions.

The mood between Greece's leftist government and its euro zone partners, especially Germany, has deteriorated in the last few weeks, with personal recriminations flying between ministers and calls from Athens for Berlin to pay war reparations.

The paper said at last week's meeting the Greek representative just asked where the money was "like a taxi driver", according to sources, and insisted his country would soon be bankrupt.

The euro zone sources told the paper that Greece's creditors do not believe this is the case and that it would be a domestic political issue if Athens is unable to fully pay salaries and pensions.

The paper also said that German Finance Minister Wolfgang Schaeuble, who has taken a tough line toward Greece in bailout talks, would have to get the Bundestag lower house of parliament to vote on any fundamental changes to the reform program.