"I support all forms of political pressure but I currently do not see a role for the military," De Maizière told reporters while on a trip to Washington, rejecting "automatic" military action in response to Syria's chemical weapons.
"Efficient military action would be extraordinarily complex and costly," he warned on the sidelines of the 20th anniversary tribute to the Holocaust Memorial Museum in the US capital.
He appeared to be referring to President Barack Obama's past warnings that Syria's use or movement of chemical weapons would constitute a "red line" that could prompt more direct US intervention in the civil war.
The United States said Thursday for the first time that Syria had likely used chemical weapons on a small scale against rebel forces, but emphasized spy agencies were still not 100 percent sure of the assessment.
Obama on Friday promised a "vigorous investigation" into the reports and renewed his warning that proof of their use would be a "game changer."
De Maizière meanwhile urged Germany's Western allies to conduct a joint inquiry into the alleged use of chemical arms.
"We do not have enough information yet," he said.
De Maizière was due on Tuesday to meet his US counterpart Chuck Hagel for talks which would include Germany's potential purchase of three attack Reaper drones and four ground stations.
Such a purchase will be approved by German authorities in May, Der Spiegel magazine's online edition reported on Tuesday morning. The US Congress apparently gave its approval for the sale on April 10th.
The initial request from Germany for the drones was made at the start of last year. US forces use the Reaper as well as Predator B drones for attacks in Afghanistan and along the Pakistan border.
De Maizière wants to get a basic decision on the purchase before September's general election, the magazine reported, although parliament will not be asked for its approval until afterwards. The Bundeswehr currently uses unarmed Heron 1 drones in Afghanistan, but the agreement for their use runs out in October 2014, the magazine said.
The talks will also cover plans for Afghanistan after the 2014 end of the Nato military mission there. Germany was the first Nato member to sign up for a continued training and advisory mission, and promised up to 800 soldiers. The US has not yet made a commitment.