Germany's defence minister said Tuesday she wants the armed forces to be able to use armed drones under certain conditions.

A day before lawmakers debate the controversial issue, Ursula von der Leyen told Wednesday's edition of the Sueddeutsche Zeitung newspaper that she backed Germany having the option of drones capable of being armed if deployments were approved by parliament.

According to the pre-released comments, she said that in the case of a mission, parliament would be able "to decide on the question of arming the drones for the protection of the troops sent ... based on the concrete case".

The issue of drones has long generated an ethical debate in Germany, which does not use unmanned aircraft to fight battles but only for surveillance and reconnaissance missions in places such as Afghanistan.

Even reconnaissance drones are controversial in Germany due to their spying capabilities which evoke dark memories from past fascist and communist regimes.

Von der Leyen, who took over the portfolio under Chancellor Angela Merkel's "grand coalition", said she believed Germany had to join European efforts to develop drones capable of being armed.

"For such a project, that takes at least a decade, we will now look for partners," she told the newspaper.

Germany currently leases Israeli Heron reconnaissance drones.

Last year Von der Leyen's predecessor, Thomas de Maiziere, also called for combat drones to be incorporated into the air force, saying their lack created a disadvantage.

Germany abandoned last year a planned Euro Hawk programme for unmanned surveillance aircraft with costly consequences over fears that aviation authorities would not certify it.