"None of us can exactly predict economic developments," she said, adding there were unknowns about the costs of integrating migrants and fighting the causes of the influx of refugees.

"There is an element of uncertainty but we are still trying to get a balanced budget," Merkel said after a meeting with the head of Germany's DGB confederation of trade unions.

Germany achieved a bigger than-expected budget surplus of 12.1 billion euros last year.

(Reporting by Madeline Chambers; Editing by Noah Barkin)