Brussels: European leaders are considering holding an emergency summit on Greece this weekend but any decision will depend on the outcome of a meeting of finance ministers this Thursday, sources said.
Athens and its EU-IMF creditors are locked in a desperate stand-off over a deal to save Greece from a possible default at the end of the month.
One source said an extraordinary summit was "possible" and if it went ahead would "probably" be on Sunday.
A second said a weekend summit "cannot be excluded, but everything depends on the outcome of the Eurogroup" meeting of eurozone finance ministers on Thursday, adding that "these are ideas being floated" rather than a specific plan.
Any meeting this weekend would come just days before all 28 leaders are to hold a scheduled summit in Brussels on June 25-26.
Preben Aamann, spokesman for the European Council, said there was no guarantee that European leaders could themselves resolve a problem that finance ministers had not been able to.
"Next and hopefully decisive step is the Eurogroup Thursday," Aamann said.
"Any further step will be decided in light of the Eurogroup outcome. There should be no illusions that an agreement becomes easier, more advantageous over time or at the level of heads of state and government."
It was not immediately clear if any summit would involve just the leaders of the 19 eurozone countries or the wider European Union, they said.
