German President Horst Koehler has announced his resignation, saying the decision takes effect immediately.
The move follows criticism of recent comments Koehler made about Germany's military mission as part of an international coalition in Afghanistan.
Koehler said in a radio interview after a recent visit to Afghanistan that the German public is slowly coming to terms with the idea that Germany must be prepared to use military force far away from home.
He said such action was conceivable to protect German interests such as "free trade routes" or to prevent regional instability.
Koehler's critics accused him of advocating a form of "gunboat diplomacy."
compiled from agency reports