"I have the impression that some of the attacks carried out on the German army also have that sort of background," Jung told German public radio Deutschlandfunk, saying that opium exporters were financing terrorism in Afghanistan.

"We'll make clear that we want to support the Afghan armed forces battling the drug world," Jung added.

He was referring to a parliamentary vote expected to be held in Berlin on October 16 or 17 on extending authorization for the German troops in Afghanistan and raising the contingent's size from 3,500 to 4,500 personnel.

Missions for German troops abroad are defined by the parliament in Berlin, so Jung would not have authority on his own to redeploy German peacekeepers to anti-drug operations.

Germany's Greens Party immediately said Sunday it would vote against German troops taking over anti-drug work.