German Chancellor Angla Merkel defended the validity of Germany's Afghan mandate in parliament on Thursday.

In the last two weeks, seven German soldiers were killed and thirteen others injured during Taliban ambushes in northern Afghanistan, aggravating the unpopularity of Germany's Afghan mission in the country.

"This mandate is valid, over and above any sensible doubt under international or constitutional law," Merkel said.

In recent months, both Merkel and the defense minister, Karl-Theodor zu Guttenberg, have acknowledged that the conflicts in Afghanistan could be described as a "war", which aroused a question about the legality of German mission in Afghanistan.

Opposition leader Sigmar Gabriel of the Social Democrats (SDP) has questioned the validity of the current mandate, because parliament only authorizes the German military to take part in "armed conflict" in the region, not a "war" which is legally defined as a conflict between states.

But Merkel said the parliament had been fully aware of conditions in Afghanistan when they approved extension of the military mandate earlier this year.

"We can't expect bravery from our soldiers, if we lack the courage to stand up for what we agreed to," she said.