Pro-Russian separatists from the Chechen "Death" battalion walk during a training exercise in the territory controlled by the self-proclaimed Donetsk People's Republic, eastern Ukraine, December 8, 2014. Maxim Shemetov/Reuters Former Soviet leader Mikhail Gorbachev warned that tensions between Russia and European powers over the Ukraine crisis could result in a major conflict or even nuclear war, in an interview to appear in a German news magazine on Saturday.

"A war of this kind would unavoidably lead to a nuclear war," the 1990 Nobel Peace Prize winner told Der Spiegel news magazine, according to excerpts released on Friday.

"We won't survive the coming years if someone loses their nerve in this overheated situation," added Gorbachev, 83.

"This is not something I'm saying thoughtlessly. I am extremely concerned."

Tensions between Russia and Western powers rose after pro-Russian separatists took control of large parts of eastern Ukraine and Russia annexed Crimea in early 2014.

The United States, NATO and the European Union accuse Russia of sending troops and weapons to support the separatist uprising, and have imposed sanctions on Moscow. Map depicts the larger confrontation between Russia and NATO and the possible return to Cold War power dynamics in Europe. Mike Nudelman/Business Insider

Russia denies providing the rebels with military support and fends off Western criticism of its annexation of Crimea, saying the Crimean people voted for it in a referendum.

Former Soviet president Mikhail Gorbachev looks on during a presentation of his new book "After Kremlin" in Moscow December 26, 2014. Sergei Karpukhin/Reuters Gorbachev, who is widely admired in Germany for his role in opening the Berlin Wall and steps that led to Germany's reunification in 1990, warned against Western intervention in the Ukraine crisis.

"The new Germany wants to intervene everywhere," he said in the interview. "In Germany evidently there are a lot of people who want to help create a new division in Europe."

The elder statesman, whose "perestroika" (restructuring) policy helped end the Cold War, has previously warned of a new cold war and potentially dire consequences if tensions were not reduced over the Ukraine crisis.

The diplomatic standoff over Ukraine is the worst between Moscow and the West since the Cold war ended more than two decades ago.

(Reporting by Erik Kirschbaum; Editing by Sam Wilkin)