German soldiers load armored vehicles of the type "Marder" on a train at the troop exercise area in Grafenwoehr, southern Germany | Armin Weigel/AFP via Getty Images German foreign minister voices skepticism on NATO spending target Politicians shouldn’t make promises ‘they can’t fulfill later on,’ says Sigmar Gabriel.

German Foreign Minister Sigmar Gabriel said Wednesday that NATO countries should not all have to meet a rigid target of spending 2 percent of gross domestic product (GDP) on defense, Reuters reported.

"I have a concern that politicians make public promises that they can't fulfill later on," Gabriel said during a state visit to Estonia. "There is no apodictic 2 percent goal but rather ... we should be moving in that direction."

The issue of defense threatens to drive a wedge between the main parties in Germany's coalition government, which is divided over how much the country ought to be spending, ahead of federal elections this fall.

Chancellor Angela Merkel and Defence Minister Ursula Von der Leyen, both Christian Democrats, support an increase in defense spending — currently at 1.2 percent of Germany's GDP — to meet NATO's recommended target. Gabriel, a Social Democrat, had previously warned that an exclusive focus on defense spending could unleash a new arms race.

"I don't know where this money should come from," Gabriel said last month, in response to Merkel's statement that Germany would do "everything we can in order to fulfill this commitment," referring to a 10-year plan to ramp up Germany’s military budget by 2024, which was agreed among NATO member countries at a summit in Wales in 2014.

European countries are under pressure from the Trump administration to share more of the burden for their security. In a speech to Congress on Tuesday, Trump said, "our partners must meet their financial obligations.”

Were Germany to meet the NATO spending target, its military budget would jump from €37 billion to more than €60 billion, making it by far the largest military power in Europe.