According to the report published on Thursday by the Ministry of Finance, getting out of the debt fold would require 6 billion euros in cuts or tax increases by 2019.
The sustainability is estimated at up to five percent of the Gross National Product.
"It means that the Finnish economy is lacking 10 billion worth of revenue every year in order to cover the expenditure," said Stubb in a statement.
The premier expressed hope that the country would cope without savings.