Moscow has sought to wrest a string of concessions from the US and its Western allies

Senior US and Russian officials were formally launching special talks on strategic stability on Monday as part of a flurry of diplomatic activity in Europe this week aimed at defusing tensions over a Russian military build-up on the border with Ukraine. Russian Deputy Foreign Minister Sergei Ryabkov and his delegation arrived under Swiss police escort at the US diplomatic mission for face-to-face talks with Wendy Sherman, the US deputy secretary of state, and her team.

The meeting is part of "Strategic Security Dialogue" talks launched by Presidents Joe Biden and Vladimir Putin during a June summit in the Swiss city.

After an informal working dinner on Sunday, Ryabkov predicted "difficult" talks in Geneva that are to be followed by a NATO-Russia meeting in Brussels on Wednesday and a meeting of the multilateral Organisation for Security and Cooperation in Europe in Vienna on Thursday.

Moscow has sought to wrest a string of concessions from the US and its Western allies, including guarantees that NATO will no longer expand eastward into former Soviet states like Ukraine, along whose border Russia has amassed an estimated 100,000 troops in steps that have raised concerns about a possible deeper military intervention there.