Greece's extraordinary proposal — amid fears it would be kicked off the common euro currency as soon as next week — capped days of turmoil in the Mediterranean nation, which has shuttered its banks to stem the panicked withdrawal of euros.

But German Chancellor Angela Merkel said her country would not "negotiate anything new at all" before a Greek referendum planned for Sunday, Germany's DPA news agency quoted her as telling German politicians.

European Union leaders have cast the plebiscite as a vote on whether the nation should remain in the euro zone. But Greece's government has tried to confine question to the tougher terms demanded to keep alive the current bailout program — which Greek leaders say they cannot accept after years of recession that has gutted the economy and driven unemployment above 25 percent.