Putin's war on Ukraine also 'war against unity of Europe', says German president
"We must not let ourselves be divided, we must not let the great work of a united Europe that we have begun so promisingly be destroyed," he said in a speech in the western German city of Paderborn.
"This war is not just about the territory of Ukraine, it is about the double shared foundation of our values and our order of peace," he said.
But defending these values also means being prepared to "accept significant disadvantages", he warned, without giving further details.
"Are we ready for that? We are all facing this question – today and in the days, weeks and months to come," Steinmeier said.
"Russia is not only questioning the borders, it is not only occupying the territories of an independent and sovereign neighbouring state, it is even challenging the statehood of Ukraine," he added.