German Chancellor Angela Merkel on Monday said she was not certain whether Germany could pull out its peacekeeping troops from Afghanistan by 2014 as planned, as she made a surprise trip to the unrest-torn country.

Despite progress made in the political reconciliation with armed groups such as the Taliban, it had not yet reached the point that Germany could announce "we can pull off today," Merkel said.

"Therefore, I can not say we can do that by 2013 or 2014, as the will is there, we want to do that, and they're working," she said.

The German chancellor's trip to Afghanistan, the fourth since she took office in 2005, came just one day after a US soldier went amok and killed 16 people in an Afghan village.

Speaking to German troops stationed in Mazar-i-Sharif, Merkel stressed that in addition to the political reconciliation process with armed groups, civilian reconstruction initiatives with the involvement of international donors were also essential.

Germany currently has a total of 4,900 soldiers stationed in Afghanistan as of Feb 1, ranking third in the 130,000-strong NATO-led International Security Assistance Force (ISAF) after the United States and Britain.

NATO said in January it would withdraw its combat troops from Afghanistan by the end of 2014, when Afghan forces are scheduled to take full responsibility for national security.

Merkel also paid homage to German soldiers killed in Afghanistan since NATO-led troops were first deployed to the country in 2002. Fifty-two German soldiers have been killed, 34 of them through enemy action.