Eurozone leaders have formally approved 110 billion euros of EU-IMF emergency loans for Greece at a summit in Brussels on the crisis facing the single currency.
The 16-nation group also says it will have special measures ready before markets open on Monday to protect the euro from speculators.
The Eurogroup president did not seek to minimise the dangers.
Jean-Claude Juncker said: “We are considering that the whole euro area in under attack, and we have to formulate from now until Sunday night a coherent answer of the euro area and the whole European Union to these attacks against the Euro area, which are not justified.”
The group had been criticised over its slowness to react to the Greek crisis. Germany showed particular reluctance. That prompted financial markets to pound other eurozone nations with high deficits or debts such as Spain and Portugal.
“The need to safeguard the eurozone goes beyond Greece’s problems. That is why the decisions we have taken show our common determination to work together, and to safeguard the stability of our common currency in Europe, and also safeguard the stability of Europe itself,” said Greek Prime Minister George Papandreou.
Among measures in the pipeline are a support fund for eurozone members and a mechanism to prevent the current situation from contaminating other countries.