“The view in the discussions to date has been that the provision of this large facility may enable Ireland to return to the bond markets very quickly,” Mr. Lenihan told the Irish national broadcaster RTE on Monday.

The loans to Ireland were necessary in large part because of the faltering state of the nation’s banking system, underscoring the extent to which ailing banks remain a threat to recovery two years after the financial crisis rippled through economies and pressured banks around the world into accepting bailouts.

Ireland’s aid will come from a rescue mechanism worth roughly $1 trillion that was set up in May by the E.U. and the I.M.F. to help euro zone countries spiraling toward default.

Government officials hope that the large commitment of money will calm investors and keep the crisis from spreading to Portugal and even Spain. It was fear of a market panic and looming contagion that prompted officials to press Ireland to accept aid early before its debt problem got out of control.

Some economists point out that the yields Greece must pay on its bonds are higher now than before its rescue, raising concerns that confidence in the fiscal health of troubled countries remains low.

Others, however, say that decisive action is what is needed to shift momentum toward recovery. “This may be an inflection point, when we stop digging a hole and start creating the conditions for reversing where we have slipped to,” said Pat Cox, an economist and former president of the European Parliament.

Prime Minister Brian Cowen said at a news conference on Sunday night that there would be two funds. One will back up the country’s failing banks, and another will allow Ireland to continue government operations without turning to the bond markets for help, something Dublin has said it cannot afford. The package should allow Ireland to operate without funds from the markets for as long as three years.