EU leaders are to hold another summit by Wednesday, because they will not be able to agree a rescue plan for the euro on Sunday.
President Nicolas Sarkozy of France and Chancellor Angela Merkel of Germany spoke by phone on Thursday.
Afterwards they said a crisis strategy would be discussed on Sunday and adopted at the next meeting.
The BBC reports EU leaders need to agree a second bailout for Greece, how to recapitalise banks and a stronger bailout fund.
Sunday's summit was already been delayed from 17-18 October because more time was needed to finalise a plan.
A spokesman for Chancellor Merkel said that the advantage of the additional summit would be that it would give the German parliament time to approve any changes to the bailout fund.
Chancellor Merkel was to address the Bundestag on Friday, but that has now been postponed.