German Chancellor Angela Merkel says her country must remain "clever and cautious" in handling the coronavirus crisis, as "it's not the end phase but still just the beginning".
"We will be with it for a long time," she warned parliament, ahead of an EU video summit on the crisis.
She stressed the need for European cohesion in fighting the virus.
And she said Germany should be ready to "make very different, meaning much higher contributions to the EU budget".
The extra funding should be provided "in a spirit of solidarity" and for a limited time, she said.
Italy, at the epicentre of the pandemic in Europe, has been especially vocal in urging its EU partners to jointly guarantee debt, as part of a huge rescue package.
But Germany, the Netherlands and Austria oppose any mutualisation of debt, in the form of so-called "coronabonds". Under current EU rules countries cannot be made liable for each other's debts.
On Thursday EU leaders are expected to sign off on a new €540bn (£470bn; $575bn) emergency fund to protect European workers, businesses and countries worst affected by the coronavirus outbreak. The details are yet to be worked out.
Italy and some others want the emergency funds to go as high as €1.5 trillion. One plan is to expand the EU budget so that the European Commission can provide much bigger loan guarantees.
French President Emmanuel Macron has lined up with Italy and Spain on the issue, warning that this crisis threatens the very existence of the EU. Italy, Spain and France – in that order – have the highest European death tolls from Covid-19.
On Thursday German officials said coronavirus cases nationally had risen to 148,046, and the number of deaths linked to Covid-19 had risen by 215 to 5,094.
Mrs Merkel said "it's the biggest challenge since World War Two, for the life and health of our people".
She urged "maximum discipline", to avoid stop-start lockdowns.
"We must not waste what has been achieved already," she said, praising the efficiency of Germany's healthcare system and the armed forces' assistance in the national effort.
Her government's decisions in this crisis "have no historical model", she said.
"The question of how we can prevent the virus from overwhelming our health system and subsequently costing the lives of countless people, this question will for a long time be the central question for politics in Germany and Europe."