Election winner Friedrich Merz on Tuesday ruled out a quick reform to Germany's state borrowing limits known as the "debt brake" and said it was too soon to say whether the outgoing parliament could wave through a massive military spending boost.

The leader of the far-right Alternative for Germany (AfD), the second largest party in parliament after Sunday's election, said Germany's likely next chancellor would be held hostage by left-wing parties that would seek to loosen tough fiscal rules.