"The assessment of the three institutions that have the task to make this kind of assessment -- the IMF, the European Commission and the ECB -- is that these countries will reach a sustainable debt situation at the end of their programmes," Regling told the newspaper.
"Portugal is struggling internally whether they should ask for assistance or not, we shall see, it's their decision. It's these three countries that will have serious problems for a while, but not the euro area as a whole."
"Spain overall is in much better shape. There's no programme, no need for financial emergency assistance in Spain."
Regling, who was speculated last month as being Germany's candidate for the presidency of the European Central Bank, repeated that he was happy in his current job and not a candidate.
"I am not a candidate and I'm happy to be here to manage the EFSF and to prepare the ESM," Regling said.
(Reporting by Padraic Halpin; Editing by Ron Askew)