Eurozone leaders have agreed to put emergency measures in place before the financial markets open again to prevent the debt crisis in Greece spreading to other countries.
During a late-night summit in Brussels, the 16 heads of the single currency countries said they were ready to take whatever steps were required to protect the stability of the euro area.
The leaders agreed to set up a crisis fund for all members to dip into in times of financial difficulty.
They also pledged to take “all measures needed” to speed up the process of reining in their national debts.
And they promised to strengthen financial governance, with tighter economic surveillance, more closely co-ordinated policies and more rigid rules on debt and deficit levels.
German Chancellor Angela Merkel said the “stabilisation” fund would send “a very clear signal” to market speculators to back off.
Belgium’s outgoing prime minister Yves Leterme added that the mechanism would be ready by “the end of the weekend”.
The leaders had been accused of heightening market uncertainty with a lack of action on euro members with high deficits or debts and low economic growth.
Stock markets around the world fell sharply this week because of fears that Greece’s debt problems would halt the global economic recovery.
The US, Japan and Canada expressed their growing concerns to France, Germany, Italy and Britain during a G7 conference call on Friday.
Barack Obama also spoke to Ms Merkel, calling for a “strong policy response” extending to the wider “international community”.
The 110bn euro (£95bn) bail-out of Greece was formally signed off at the crisis talks, with the eurozone to provide 80bn (£69bn) over three years and the IMF offering a further 30bn (£26bn).
All 27 EU finance ministers, who have been given the task of setting up the crisis fund, will meet on Sunday in Brussels to approve the special measures.
