Most of the 3,000 German troops deployed in Afghanistan are based in this northern Afghan city.
The German government decided on Wednesday to extend by ten months its military presence in the country until the end of 2014. The lower house of parliament, the Bundestag, must still give its approval.
It is the first visit to Afghanistan by the Social Democrat minister since he entered the coalition government of Chancellor Angela Merkel that emerged from September's legislative elections.
It comes as the UN said the number of civilians killed and wounded in Afghanistan rose 14 per cent last year.
More than 50,000 NATO-led combat troops who are still in Afghanistan are due to leave by the year-end.