Jets for Afghanistan

"We are prepared in principle to provide intelligence capacity of this kind," Gernot Erler told Deutschlandfunk radio.

Erler said that sending the planes would require a change to the parliamentary mandate covering German forces already deployed in Afghanistan, but his ministry later clarified that this was "not necessarily" the case and the request was still being studied.

Press reports say Germany has been asked to send five or six Tornadoes, which could be used in missions across Afghanistan, including in the south where fighting is fiercest.

Germany currently has 2,700 troops serving in the NATO-led International Security Assistance Force (ISAF) in Afghanistan but has resisted pressure to redeploy any of them from the relatively stable calm north to trouble spots in the south and east.

Other NATO member states have urged Germany to send troops to the south to help overstretched forces face up to the increasingly militant Taliban.

To date, Germany has resisted that pressure.

250 more troops needed

The Tornado jets would require 250 additional troops, according to Bundeswehr spokesman Thomas Raabe. He confirmed that the aerial surveillance would extend beyond the areas currently being patrolled by German troops.

"This is a request for a capacity that could be deployed in other parts (of Afghanistan)," Raabe said.