BRUSSELS, Jan. 12 (REUTERS) — Senior NATO and Russian officials were meeting Wednesday to try to bridge seemingly irreconcilable differences over the future of Ukraine, amid deep skepticism that Russian President Vladimir Putin’s security proposals for easing tensions are genuine.

The talks comes during a week of high-stakes diplomacy and a U.S.-led effort to prevent preparations for what Washington believes could be a Russian invasion of Ukraine. Moscow denies it is planning an attack. Still, its history of military action in Ukraine and Georgia worries NATO.

NATO Secretary-General Jens Stoltenberg, Russian Deputy Foreign Minister Alexander Grushko and Deputy Defense Minister Alexander Fomin were stern-faced as they posed for the media before the NATO-Russia Council. There was no public handshake, although the Russian delegation fist-bumped officials from the 30 NATO member countries inside the meeting venue.

Deputy Secretary of State Wendy Sherman led the U.S. team at NATO headquarters in Brussels.

The meeting, the first of its kind in over two years, was due to run for about three hours. The NATO-Russia Council, their chief forum for talks, was set up two decades ago but full meetings paused when Russia annexed Ukraine’s Crimean Peninsula in 2014. It has met only sporadically since, the last time in July 2019.

With around 100,000 combat-ready Russian troops backed by tanks, artillery and heavy equipment massed just across Ukraine’s eastern border, Wednesday’s gathering has taken on great significance, yet it still seems destined to fail.