BRUSSELS--All sides need to be "flexible" to reach a deal on how to finance Greece's budget gap and bring its debt back to a sustainable level, French Finance Minister Pierre Moscovici said late Monday.

Speaking to reporters after a meeting of euro-zone finance ministers, Mr. Moscovici said there are various ways Greece's funding needs can be met.

"We need to think about the financing of Greece's needs until 2017 and the sustainability of Greek debt. Should we give two more years for that? We're in favor of it," he said. "Now we need to be pragmatic. Each one of us needs to be flexible on their red lines."

Until now, euro-zone governments have ruled out contributing to Greece's funding needs by taking a cut on their holdings of Greek debt.

He said finance ministers must make a decision on how to find the extra money at next week's meeting.

Mr. Moscovici said he is also in favor of giving Greece an extra two years to return its debt to a sustainable level, a position backed by Jean-Claude Juncker, head of the Eurogroup of finance ministers on Monday. International Monetary Fund Managaing Director Christine Lagarde said Monday she opposed that.

"We can actually consider the date of 2022" for debt sustainability, Mr. Moscovici said. "There are different points of view on that issue, with different analysis around the table."

Write to Gabriele Parussini at Gabriele.Parussini@dowjones.com