German Finance Minister Wolfgang Schaeuble said on Thursday that the situation in Greece was "serious" and the country would not receive new aid until it met the fiscal conditions set out for it by its international lenders.

"Ladies and gentlemen, the situation is serious in Greece," Schaeuble said in a speech in the Bundestag lower house of parliament.

"At the moment the troika mission is suspended. There can be no illusions here. As long as this mission cannot confirm that Greece has fulfilled the conditions, then the next aid tranche cannot be paid. There is no wiggle room here."