WATCH: State Department spokesperson Ned Price holds briefing amid talks with Russia

Senior U.S. and Russian officials launched special talks Monday aimed at defusing tensions over a Russian military buildup on the border with Ukraine, part of a flurry of diplomatic activity in Europe this week.

Watch Price’s remarks in the payer above.

Russian Deputy Foreign Minister Sergei Ryabkov and his delegation arrived under Swiss police escort at the U.S. diplomatic mission in Geneva for face-to-face talks with Wendy Sherman, the U.S. deputy secretary of state, and her team. The meeting is part of “Strategic Security Dialogue” talks on arms control and other broad issues launched by Presidents Joe Biden and Vladimir Putin during a June summit in the Swiss city.

No major breakthrough was immediately in sight.

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

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

Sherman “stressed the United States’ commitment to the international principles of sovereignty, territorial integrity and the freedom of sovereign nations to choose their own alliances” at the dinner, said State Department spokesman Ned Price, a reference to Ukraine and its aspirations of joining NATO. Many analysts say any such move would be years away at best.

Sherman “affirmed that the United States would welcome genuine progress through diplomacy,” Price said.

The U.S. has played down hopes of significant progress this week and said some demands – like a possible halt to NATO expansion – go against countries’ sovereign rights to set up their own security arrangements, and are thus non-negotiable.

But U.S. officials have expressed openness to other ideas, like curtailing possible future deployments of offensive missiles in Ukraine and putting limits on American and NATO military exercises in Eastern Europe – if Russia is willing to back off on Ukraine.

U.S. Secretary of State Antony Blinken said bluntly Sunday that he doesn’t expect any breakthroughs in the coming week. Instead, he said a more likely positive outcome would be an agreement to de-escalate tensions in the short term and return to talks at an appropriate time in the future.