Russia's prime minister said the world has slid into a new Cold War, for which he blamed Nato and what he said was the alliance's "unfriendly" policy towards Moscow. Speaking a high-profile conference in Germany Dmitry Medvedev said East-West relations have significantly worsened since 2007, when President Vladimir Putin warned from the same stage that tensions would spiral if the West was to build a missile defence system.

"The picture is more grim; the developments since 2007 have been worse than anticipated," Medvedev told the Munich Security Conference. "Nato's policies related to Russia remain unfriendly and opaque — one could go so far as to say we have slid back to a new Cold War".

The prime minister lashed out at sanctions imposed on Russia over the conflict in Ukraine saying are "a road that leads nowhere" and might backfire, while aggravating tensions. "The longer the sanctions continue chances for the Europeans to keep their position at the Russian market as investors and suppliers are fading," he explained. "That's why one has to act quickly."

Medvedev was quickly rebuked by US Secretary of State John Kerry who said sanctions will stay in force until the Minsk agreements on Ukraine were fully implemented. Earlier Nato Secretary General Jens Stoltenberg hit back at the Russian prime minister, saying a firm stance against Moscow was needed although the alliance did "not want a new Cold War".

"Russia's rhetoric, posture and exercises of its nuclear forces are aimed at intimidating its neighbours, undermining trust and stability in Europe," he said. In other comments, Medvedev claimed terrorists were infiltrating Europe disguised as migrants and denied Russia was bombing civilians in Syria.