Reforms to the European Union's budget pact must not water down the threat of sanctions against countries that break the rules, Luxembourg's prime minister said in a newspaper interview.
Mr Jean-Claude Juncker, whose country takes over the EU presidency next month, said the changes must not tamper with the substance of the Stability and Growth Pact, according to a report in Germany's Boersen-Zeitung.
EU finance ministers are due to draft changes to the pact at their next meeting in mid-January, and the reforms will be presented to government leaders in March.
Mr Juncker said the revamped rules should allow budget deficits to be "more easily measured and understood", while still keeping open the possibility of action against countries which overshoot deficit limits.
"There must still be recommendations, and also the instrument of threatening sanctions must not be watered down," he told the newspaper.
Luxembourg is due to take over the rotating presidency of the EU on January 1st and Mr Juncker has made clear he opposes excluding different types of spending, such as military and research, from the budget rules.
The European Commission has proposed giving euro zone states more flexibility to run deficits during economic downturns provided they have saved money during good years.
The review was triggered by a controversial decision by EU finance ministers last year to suspend disciplinary action against France and Germany after they repeatedly breached the 3 percent of gross domestic product deficit limit.