EU leaders have pledged 125 billion euros in support for eastern Europe and the International Monetary Fund.
Under an agreement at a summit in Brussels on Friday, loans available to eastern Europe will be doubled to 50 billion euros and 75 billion euros added to the IMF's lending capacity.
British Prime Minister Gordon Brown said they had agreed to do "whatever is necessary to restore jobs and growth".
An existing credit line of 25 billion euros is being rapidly depleted after Hungary and Latvia withdrew nearly 10 billion euros. Other countries starting with Romania, are likely to follow soon.
Earlier this month, EU leaders ruled out a regional bailout plan for eastern Europe, and opted instead to extend help to countries on a case-by-case basis as trouble emerges.