BERLIN (AP) — Chancellor Angela Merkel made a one-day trip Monday to visit German troops in northern Afghanistan and offered President Hamid Karzai her condolences over the killing of 16 civilians by a U.S. solider, the government said.

Merkel arrived in Mazar-e-Sharif early in the morning. She originally planned also to visit Kunduz, another northern area where German troops are based, but bad weather meant it wasn’t possible to fly there.

The chancellor’s previously planned but unannounced visit came a day after an American soldier allegedly shot to death 16 civilians in southern Afghanistan and burned their bodies.

Merkel spoke with Karzai by phone from Mazar-e-Sharif and offered her "personal condolences" following "the terrible actions of a U.S. soldier," a German government spokesman said.

She also assured him that the NATO-led security force in Afghanistan will do everything to clear up what happened, the spokesman said on condition of anonymity in line with department rules.

Germany has some 4,800 troops in the NATO-led force in northern Afghanistan. Television footage showed Merkel paying tribute at a memorial to fallen soldiers in Mazar-e-Sharif shortly after her arrival. Over the years, 52 German soldiers have died in Afghanistan.

By the end of January 2013, the government aims to get troop numbers down to 4,400. That’s part of plans by the U.S. and other allies to withdraw combat troops and hand over responsibility for security to Afghan authorities by the end of 2014.

Speaking of those plans during her visit, Merkel said that there had been some progress in Afghan reconciliation efforts but not to the extent that Germany is able to say it could withdraw now.

"So I cannot yet say, will we manage that by 2013-14," she said. "The will is there, we want to manage it, and it is being worked on."