Germany is planning a major cut in its military forces in Afghanistan next year, according to a government document seen by AFP Thursday.

Under the plan, the current force, up to 5,350-strong, will be reduced to 4,900 from next February, with a further 500 soldiers leaving the country by early 2013.

The plan was outlined by German Defence Minister Thomas de Maiziere and Foreign Minister Guido Westerwelle in a letter to parliamentary groups, obtained by AFP.

Behind the decision, it said, was the "current and forecasted security situation", as well as the state of training of Afghan security forces.

Germany, which has the third biggest force in Afghanistan behind the United States and Britain, said at the start of the year that it aimed to begin pulling its military forces out, eyeing 2014 for complete withdrawal.

Polls have shown the mission, the first major Bundeswehr deployment outside of Europe since World War II, has been consistently unpopular in the country.