Greek Prime Minister Antonis Samaras has reiterated his belief that exiting the euro would be a "catastrophe" for his country.
In an interview with the Washington Post, he called again for more time for Greece to implement spending cuts.
There are indications creditors are considering giving Greece more time.
His comments come as a leading German politician said Germany was unlikely to agree to further help for Greece beyond that which has already been agreed.
Greece is currently trying to finalise a package of 11.5bn euros ($15.1bn; £9.3bn) of spending cuts over the next two years.
The measures are needed to qualify for the next 33.5bn-euro instalment of its second 130bn-euro bailout.
Mr Samaras said Greece had to "make sure that we abide by what we have signed because we believe that what they call a 'Grexit' is not an option for us. It would be a catastrophe."
However, he did say that Greece would benefit from more time to implement further austerity measures.
"Instead of the [cuts package] taking place over two years, it would be best if it were to take place over four years.
"We are talking about an extension to 2016," he said.
On Friday, at a Eurogroup finance ministers meeting in Nicosia in Cyprus, International Monetary Fund (IMF) head Christine Lagarde hinted that Greece's creditors may be receptive to giving the country more time.
"Greece has already produced a huge effort but will have to continue to do so," Ms Largade said.
"The target when it comes to achieving debt sustainability is very high, so there are various ways to adjust. Time is one that needs to be considered as an option."
The European Union, the European Central Bank and the IMF are due to report next month on whether Greece has met the conditions laid down for the next instalment of its second bailout.
Greece was given a 110bn-euro package in May 2010 and a further 130bn euros in October 2011, along with a 100bn-euro debt write-off.
A prominent German politician suggested that once the second bailout had been paid out in full, another would not be forthcoming.
"I can't imagine that a further package for Greece would get a majority in the Bundestag, or in the governing coalition," said Rainer Bruederle, parliamentary leader of the Free Democrats Party.
"We Germans are helpful, but we're not stupid."