More Military Aid

"I am in favor of extending our assistance in training and equipping the Afghan army," Steinmeier told the mass-circulation Bild newspaper.

The remarks came amid a debate that has taken on renewed urgency in Germany since two German engineers were kidnapped in Afghanistan on July 18. One has been killed and the other is still being held by his abductors.

Steinmeier said Germany could begin considering withdrawing its 3,000 ground troops engaged in a reconstruction mission in the north of Afghanistan only once Afghan forces could guarantee security.

"If we give up now, then the Taliban will have reached their goal," the Social Democrat said.

'Aid not occupiers'

Ruprecht Polenz, head of the German parliament's Foreign Affairs Committee and a member of Chancellor Angela Merkel's Christian Democrats (CDU), spoke out against repeated calls for more Western troops to be sent to Afghanistan.

Polenz was responding to a renewed call from NATO General Secretary Jaap de Hoop Scheffer in Germany's weekend press for Germany to give more military assistance to Afghanistan.

Polenz said it was possible that "the German troop contingent could be slightly strengthened," but he stressed the need for Afghan forces to play a larger role.

"We must avoid that the foreign forces are seen as an occupying army," Polenz said.

Increasingly controversial

Germany's three separate deployments to Afghanistan come up for renewal by parliament in the autumn.

Apart from the 3,000 troops in the north, six reconnaissance jets are assisting the International Security Assistance Force (ISAF) in detecting Taliban positions, and a number of German troops are deployed to the US-led counter-terrorism Operation Enduring Freedom (OEF).

The deployment of the Tornado spy planes and the elite troops to OEF are increasingly controversial within Merkel's broad coalition that includes both main parties, the CDU and the SPD.