Brussels - Greek Prime Minister George Papandreou gave European leaders until next week to spell out what financial aid they are prepared to give him as signs mount that a pact agreed just three days ago is fraying.

"This is an opportunity we should not miss," Papandreou told reporters in Brussels on Thursday. "When you have that instrument in place, that could be enough to tell the markets hands off, no speculation, let this country do what it's doing."

European Union finance ministers this week agreed to a framework to rescue Greece should it struggle to finance the EU's biggest budget deficit.