French President Nicolas Sarkozy said here late on Monday that European Union leaders would further discuss debt problems in Greece in the next few days, while it was not sure whether an extra eurozone summit would be necessary yet.

"We have high hopes that there will be an agreement in the coming days," Sarkozy told reporters after a half-day summit of European Union leaders in Brussels.

Negotiations between Greece and private bondholders over debt-restructuring made some progress over the weekend but failed to make a deal, which should be a precondition for the EU and the International Monetary Fund to implement a second rescue program to the country.

The Greek issue continues to hang over Europe as it could run out of money as early as mid-February without the second bailout, while prior to the summit, Germany's proposal of introducing a European commissioner to supervise Greek public finances had caused outrage in Athens.