The interest rate should be less related to moral hazard and essentially related to debt sustainability, according to Mr Rehn.
'It is important that in defining the interest rate, debt sustainability is firmly taken into account and therefore the commisssion already some time ago proposed a reduction of the interest rate for Ireland in order to help Ireland overcome its debt burden in the same way as Greece or Portugal,' Mr Rehn said.
He said that he expects EU finance ministers to reach an agreement on Ireland's interest rate shortly.
Speaking at a press conference about the Portuguese bailout agreement this afternoon, Mr Rehn said that that agreement was an ambitious but realistic programme.
He said the interest rate on Portugal's bailout was calculated according to the formula that was agreed some time ago in the euro group.
'This means that we will follow the IMF pricing policy and we will have a small premium, and this will lead to the interest rate to be somewhere in the scale of over 5.5%, but clearly below 6%', he said.
He also said the programme deserves the support of the European Union.
'I trust that the EU finance ministers will endorse it on May 16.'
He said that there was not a crisis of the euro but a sovereign debt problem in several eurozone countries.
