Bloomberg: Prime Minister Alexis Tsipras is under pressure.

(Bloomberg)Prime Minister Alexis Tsipras is under pressure to show how far he’s willing to go to keep Greece in the euro as European leaders express skepticism he can deliver tough reforms.

“Realistic proposal from Athens needs to be matched by realistic proposal from creditors on debt sustainability to create win-win situation,” European Union President Donald Tusk said in a Twitter post Thursday.

In the U.S., Treasury Secretary Jacob J. Lew called for an agreement that keeps the euro area intact, saying a long-term solution must include restructuring of Greece’s debt. “It is in the best interest of all parties to find a resolution.

The leaders of all 28 European Union countries will meet in Brussels on Sunday to decide their response to Greece’s proposals. Even if there is a deal this Sunday, the country’s exit from the currency bloc is more likely than not for the next two to three years, according to Citigroup Inc. Chief Economist Willem Buiter. Today Tsipras may be ready for flexibility.

“Greece is obviously working to secure an immediate deal, but it must be a deal that opens a window out of the current crisis,” Energy Minister Panagiotis Lafazanis. “We don’t want a third memorandum“.