A senior European official says the very future of the EU is at stake in the current debt crisis.
Finance ministers from countries using the euro are meeting in Brussels on Tuesday to discuss how to prevent Ireland's debt problem affecting other eurozone members.
Greece and Portugal are also struggling with huge debt.
European Council president Herman Van Rompuy said that if the euro failed, so too would the EU.
However, the BBC reports he added he was "very confident" the problems could be overcome.
But he added: "We all have to work together in order to survive with the eurozone, because if we don't survive with the eurozone we will not survive with the European Union."
However, Mr Rehn said the latest crisis was not a matter of survival for the euro - although it was a very serious problem for the banking sector in the Irish Republic.
The Irish Republic has insisted it does not need EU help.
But there is intense speculation that both it and Portugal may be forced to use EU bail-out money.