Finnish Foreign Minister Timo Soini attends the opening of the 24th Annual Session of the OSCE Parliamentary Assembly in Helsinki, Finland on July 6, 2015. Reuters/Antti Aimo-Koivisto/Lehtikuva

HELSINKI (Reuters) - Greece will be a headache for the euro zone for decades, Finland's euroskeptic foreign minister said, and called for the International Monetary Fund to participate in the Greece's new bailout package.

"Unfortunately, this problem will be in front of us for decades, I would say, if the euro zone stays together," foreign minister Timo Soini said in an interview with public broadcaster YLE on Monday.

IMF's participation in the new 86 billion-euro bailout is uncertain because the fund demands debt reliefs to ease the burden on Greece.

"An absolute debt cut, I think, is out of question, Germany too is against it ... On other issues (maturities, interest rates) we must negotiate," Soini said.

"IMF's participation would also strengthen the expertise in the package, so that the programs will actually be carried out by Greece."

The Finnish parliament's grand coalition last week approved the bailout deal.

Soini's nationalist the Finns party is known for opposing euro zone bailouts but had to support the new Greek deal to be able to keep a seat in the coalition government which it joined in May for the first time.

"I still think bailout policy is bad policy ... But in politics, one must make unpleasant decisions," he said.