Alexander Lukashevich, head of the Russian delegation in Vienna, told reporters after the talks he was “disappointed” by what he had heard.

“We’re trying to set our differences in a diplomatic way,” he said. “If we fail, we should provide guarantees (for our security) by other means.”

Poland’s foreign minister Zbigniew Rau, launching his country’s year-long chairmanship of the OSCE, said Europe was closer to war than any time in the last 30 years.

Michael Carpenter, the US permanent representative to the 57-nation grouping, warned after the talks that the “drumbeat of war is sounding loud, and the rhetoric has gotten rather shrill.”

“We’re facing a crisis in European security,” he said.

Washington is preparing how it will respond if talks fail and Russia does go ahead with an invasion of Ukraine.  

Senate Democrats on Wednesday unveiled new potential sanctions against Russia that target President Putin personally and the Kremlin’s key banks.