Representatives of NATO and Russia have tried and failed to resume formal talks through a council that has been largely inactive since 2014, when Moscow occupied and annexed parts of neighbouring Ukraine.
Jens Stoltenberg, head of the NATO military alliance, spoke to Russian Foreign Minister Sergei Lavrov at the Munich Security Conference Friday in an effort to convene high-level talks under the auspices of the NATO-Russia Council.
The failure to agree on a meeting "illustrates there are some challenges in the relationship between NATO and Russia," Stoltenberg said without elaborating.
The news comes two days after Stoltenberg announced the military alliance would increase its presence in the Black Sea, which surrounds Russian-annexed Crimea.
NATO suspended all practical cooperation with Russia after the annexation in 2014. Representatives of the two sides have not convened the council since June of that year, although there were some other political and military contacts.
Separately, it emerged that the foreign ministers of Ukraine, Russia, Germany and France would meet in Munich in the so-called Normandy format one year after a peace deal was agreed in Minsk.
The German Foreign Ministry said the meeting would take place early Saturday on the sidelines of the conference. It is hoped it will provide new impetus for the implementation of a peace deal agreed in Minsk on February 12, 2015.
Violations of the ceasefire are reported nearly daily, but the deal's implementation is imperative if Russia wants to remove crippling Western sanctions against its economy.