Germany clocked up a bigger-than-expected budget surplus of 12.1 billion euros in 2015, which it plans to use to cover the costs of taking in so many refugees, the German Ministry of Finance said Wednesday.

"Thanks to the favorable economic trends and our forward-looking budget policy, the government has set aside a provision of 12.1 billion euros," said German Finance Minister Wolfgang Schaeuble. "We will urgently need this provision to finance the additional costs of accommodating and integrating the refugees," Schaeuble said.

Originally, Berlin had said it would set aside 5 billion euros to cover the costs of the refugee crisis. "This year, too, we don't want take up any new debt, if possible," Schaeuble said.

Germany registered 1.1 million asylum seekers in 2015, with refugees from war-torn Syria making up almost 40 percent of arrivals. It was the second year in a row that Europe's biggest economy has achieved a balanced budget, or what it terms a "black zero" in its public finances.

The ministry said government spending amounted to 299.3 billion euros in 2015, 2.6 billion euros lower than expected. At the same time, revenues totaled 311.4 billion euros, or 4.5 billion euros more than the government had anticipated. Tax revenues alone came in 1.6 billion euros higher than expected at 281.7 billion euros.

The ministry said the government's underlying or "structural" surplus stood at 0.1 percent when measured against gross domestic product (GDP). Under EU rules, member states are now allowed to run up public deficits in excess of 3 percent of GDP, and are obliged to target a balanced budget or even a surplus in the longer-term.