Merkel arrived in Kunduz in northern Afghanistan to meet German troops serving there ahead of Christmas celebrations.
She then went on to Mazar-i-Sharif, the major northern city, for talks with Afghan President Hamid Karzai and the US commander of the roughly 140,000 international forces fighting Taliban insurgents, General David Petraeus.
Berlin is to start reducing troop numbers in Afghanistan by the end of next year with a view to pulling out of the country completely by 2014.
“What we have here is not just a warlike situation,” Merkel told troops in Kunduz. “You are involved in combat as in war.”
“This is a new experience,” Merkel added on her third visit to Afghanistan while in office.
“We have heard such things from our parents talking of World War II, but that was different because Germany was the aggressor.”
Opinion polls suggest that a majority of Germans are opposed to the Afghan mission. The deployment of combat troops is controversial in a country where the legacy of World War II still colours political discourse.