Former Soviet Union leader Mikhail Gorbachev has warned that tensions between the US and Russia over Ukraine is bringing the world closer to the brink of a new Cold War.
The 83-year-old former statesman said attempts must be made to ensure that recent tensions that have arisen are brought under control.
Speaking at an event on Saturday marking the 25th anniversary of the fall of the Berlin Wall near the Brandenburg Gate, Gorbachev said a new trust needs to be built between Moscow and the West.
He also lamented recent violent events in the Middle East and growing discord between the world's major powers.
"Bloodshed in Europe and the Middle East against the backdrop of a breakdown in dialogue between the major powers is of enormous concern," Gorbachev said.
"The world is on the brink of a new Cold War. Some are even saying that it's already begun."
Gorbachev accused Western countries, particularly the US, of "triumphalism" in the years following the collapse of the Soviet Union in 1991, and suggested that the West should ease sanctions imposed on senior Russian officials over Moscow's actions in eastern Ukraine.
Before arriving in Berlin, Gorbachev spoke out in defence of Russian President Vladimir Putin, saying that the Ukraine crisis gave the US an "excuse" to victimise Russia. "I am absolutely convinced that Putin protects Russia's interests better than anyone else," he said.
Gorbachev conceded in an interview with the Interfax news agency that Putin is not above criticism, but maintained that he did not want other powers to pick on the Russian president.
The former USSR leader is credited with re-establishing friendly relations with the West. His perestroika and glasnost reforms ushered in a more liberal atmosphere, which paved the way for the collapse of communist regimes in eastern Europe and the Soviet Union in the late '80s and '90s.
On 9 November 1989, East Germany opened its borders and the Berlin Wall, which separated the eastern and western parts of the city.
Speaking to the Kremlin-sponsored TV channel RT News, philsopher and political commentator Noam Chomsky echoed Gorbachev's warnings.
Gorbachev's comments come as the Dutch foreign minister Bert Koenders warned that some victims of the Malaysia Airlines MH17 plane shot down over Ukraine may never be recovered.
More than 4,000 people have died since April, when pro-Russian separatists seized control of the eastern regions of Donetsk and Luhansk.
A fragile ceasefire has been in place since September, but elections in rebel-held areas in the east last weekend have prompted fears of a return to full-scale conflict.