The Portuguese opposition must stick to promises on austerity if it wins upcoming elections, Dutch Finance Minister Jan Kees de Jager said in an interview pre-released Sunday.

If Portugal does not stick to promises to be made to the IMF and the EU as terms of a bailout program, "then the payments to Portugal will be halted immediately," the minister said in an interview with Germany's Handelsblatt.

It has taken Portugal too long to draw the appropriate lessons from the debt crisis, Kees de Jager said. "That is worrying. Numerous finance ministers have spoken about this with concern," he said.