Germany's Foreign Minister Sigmar Gabriel warned on Saturday that the Syrian conflict was moving in a direction that spelled "acute danger of war for our close partners," referencing fellow NATO member Turkey.

Gabriel also added that the world faces multiple security challenges and the threat of major conflict in different regions in 2018.

"Predictability and reliability are currently goods in short supply in international politics," Gabriel said on the second day of the Munich Security Conference.

Gabriel slammed the "America first" approach of United States President Donald Trump, saying that close U.S. ties with a strong European Union are as much in Washington's interest as they are in Europe's.

Gabriel told world leaders and defense officials at the Munich Security Conference that with the U.S. no longer the only indisputable superpower, it makes sense to count on traditional partners in Europe for help.

At the same time, he said, it is clear that European nations also need the U.S. if they want to "shape the future and not just endure."

"Our strength in Europe is not sufficient for this. Neither the EU nor the U.S. can do it alone. We have to count on our friends and our partners," he said, adding that no country in Europe has benefited as much from American help as Germany since World War II. "We eagerly learned" principles of democracy, multilateralism, international law and free trade from the relationship with the U.S.

"Maybe this can explain why we Germans in particular are so perturbed when we look across the Atlantic — because we no longer recognize our America," he said. "Is it deeds, is it words, is it tweets we should look at to measure America?"

He urged a return to greater joint cooperation, saying now is not the time for "just pursuing individual national interests," but suggested the U.S. was going in the opposite direction, drifting toward approaches taken from powers like China and Russia who are "constantly trying to test or undermine" the EU.

"It is one thing from possible rivals or competitors, but from our friends and partners we expect that they will respect the unity of the EU," he said. "No one should try to divide the EU, not Russia, not China, but also not the United States."