By Andrea Thomas 

BERLIN--Global political crises will leave skid marks on Germany's economy, the country's Finance Minister Wolfgang Schäuble warned Monday, pointing to present conflicts in Ukraine and the Middle East.

The comments come after Chancellor Angela Merkel also said earlier Monday that tougher economic sanctions against Russia will probably hurt German businesses.

"As a result, we will have a rather difficult economic situation in the near future," Mr. Schäuble said at a conference on "20 Years of Core Europe," organized by the European Democracy Lab in Berlin.

The government has forecast the German economy to grow by 1.8% this year and 2.0% in 2015, but business sentiments deteriorated in recent months amid geopolitical uncertainties, which some economists have said might prompt the government to lower its forecast at its regular review in autumn.

Commenting on the state of the euro zone, Mr. Schäuble warned that the 18-member-strong bloc, which, for the past several years, has dealt with weak economic growth and mounting sovereign debt, isn't yet out of the woods.

"We have gotten out of the euro crisis to some degree, but we haven't turned the corner as clearly as we should have," he said, pointing to high unemployment and overly low investment levels in the area.

He reiterated Germany's position that structural reforms and sustainable fiscal policy, which means cutting deficits, are needed to overcome the crisis, and it is important for European countries to stick to the rules that they have agreed to.

Too many European finance ministers believe that public investments will help solve the area's economic problems, he criticized, adding that cheap financing isn't a panacea. "We need investments that prevail on markets," he said.

Germany had been one of the main proponents of an austerity policy during the current crisis, and has been cautious about proposals from France and Italy to focus more on growth-boosting measures and less on deficit reduction and structural reforms.

Some pessimists fear that the sovereign debt crisis, which peaked two years ago, might get back into the spotlight given the still-high debt levels in many member countries.

European Union leaders plan to discuss the economy amid concerns about the bloc's fragile recovery and low inflation in a meeting in Italy in October.

Write to Andrea Thomas at andrea.thomas@wsj.com