Dutch central bank chief Nout Wellink said Thursday he supported doubling European emergency funding to the value of 1.5 billion euros to bolster crisis-hit countries within the eurozone.

"The fund must double to 1.5 billion euros," Wellink told the Dutch financial daily Financieele Dagblad in an interview.

Asked about the private sector's participation in a new aid package to Greece, especially wanted by Germany, Wellink said it should be "truly voluntarily."

He added: "If you take the risk, then you must realise that you have to build a safety net," that is, "doubling the emergency fund," as eurozone countries discuss a plan for new financial aid to Greece.

The European Financial Stability Facility (EFSF), the body created by the European Union as a rescue buffer for EU countries facing critical problems over financing their debt, has a capacity of 400 million euros (564 million US dollars).

It is further complemented by an envelope from the European Commission and by the International Monetary Fund to a total value of 750 million euros.

Wellink steps down as central bank governor at the end of the month.