Eurozone governments would only write off part of Greece's debt in "extreme circumstances", the head of the European bailout fund, Klaus Regling, told a German newspaper Monday.
The director of the 500-billion-euro ($638-billion) European Stability Mechanism (ESM) told the business daily Handelsblatt that calls for a further "haircut" on state holdings of Greek debt would be closely scrutinised.
"A public writedown is something that is very unusual," Regling said. "It can only happen in extreme circumstances."
Private investors in Greek debt agreed to write off the bulk of the value of their holdings as part of a second bailout package negotiated earlier this year.
But so-called "official sector" bondholders, including other eurozone governments, have until now been spared such a write-off.
Greece is striving to persuade the troika of international creditors it has made enough progress in reforms and painful austerity cuts to unlock a 31.5-billion-euro slice of aid needed to stave off bankruptcy.
Eurogroup president Jean-Claude Juncker has said he hopes a meeting Tuesday will clear the way for Greece to receive the latest tranche of bailout cash.
But the EU and International Monetary Fund (IMF) are at odds over how to address and pay for Greece's soaring debt and an official sector writedown is one of the options on the table.
Regling said that regardless of whether Greece gets a debt write-down, it should manage to slash its debt by around one-third in the coming decade due to the extremely low borrowing rates of 1.5 to 2.0 percent from rescue funds.
And he dismissed reports of rancour within the so-called troika of Greek creditors -- the IMF, the European Commission and the European Central Bank -- over a key target in Greece's bailout programme.
"We've managed again and again to reach a consensus," he said, adding that he was confident the IMF would remain involved in Greece's bailout.