As the country is under heavy pressure from other European countries, especially Germany, to implement austerity and reform measures in return for fresh international aid to avoid bankruptcy, Papoulias strongly rejected warnings of a Greek exit from the eurozone in a rare burst of anger, the national news agency AMNA and several local media reported.

"I cannot accept Mr. Schaeuble insulting my country...Who is Mr. Schaeuble to taunt Greece? Who are the Dutch? Who are the Finns?" the president said in a speech at the Defense Ministry.

Schaeuble, an 82-year-old veteran of Greek resistance to Nazi forces during the Second World War, also stressed that Greece always defended with pride not only the freedom of Greek people, but the freedom of Europe.

Debt-laden Greece has depended on multi-billion-euro rescue loans from the European Union (EU) and the International Monetary Fund (IMF) to avoid default since 2010.

Without a second bailout package, the country would be unable to repay a maturing bond next month, ending up in a chaotic meltdown that could hit hard the entire eurozone.