Greece's huge debt mountain remains a "major point of concern" as eurozone finance ministers discuss whether to endorse a third bailout-for-reform deal, Eurogroup head Jeroen Dijsselbloem said Friday.

"Debt sustainability is still a major point of concern, especially for the IMF," Dijsselbloem said, adding it would be "very important" for the International Monetary Fund and Europe to agree on an approach to any debt relief.

Several of the 19 eurozone nations, especially Germany, are sceptical of the merits of a third bailout for Greece and hostile to any outright cut which would cost holders of Greek debt potentially billions.