Russia has accused the United States and its allies of "slander" as the U.S. top diplomat and Pentagon chief denounced Russia’s actions in Ukraine and elsewhere.
Secretary of State Rex Tillerson told his counterparts at NATO on March 31 that the United States was committed to Ukraine's territorial integrity and that U.S. sanctions against Russia will remain in place "until Moscow reverses the actions that triggered our sanctions."
Western nations imposed the sanctions for Russia's illegal 2014 annexation of Ukraine’s Crimea region and for its support for separatist fighters in eastern Ukraine.
"We do not and will not accept Russian efforts to change the borders of the territory of Ukraine," said Tillerson.
The secretary of state added that Washington "will continue to hold Russia accountable to its Minsk commitments," referring to the Minsk process to resolve the Ukraine crisis.
Tillerson was attending his first meeting of NATO foreign ministers amid worries about U.S. President Donald Trump's stated desire for closer relations with Moscow.
He told Ukrainian Foreign Minister Pavlo Klimkin, who was also at the meeting, that American and NATO support for Ukraine remained "steadfast" after "Russia's aggression against Ukraine."
Russia responded by accusing NATO of spreading "the myth of a 'Russian threat'" and "the slander of 'Russian aggression'" as a way to unify its members.
"The U.S. and its allies are obsessed with building up their military presence on our borders, justifying it with the need to 'restrain Russia'," the Foreign Ministry said in a statement.
Also on March 31, U.S. Secretary of Defense Jim Mattis told reporters in London that "Russian's violations of international law are now a matter of record -- from what happened with Crimea to other aspects of their behavior in mucking around inside other peoples' elections.”
Mattis was likely referring to Russia’s alleged meddling during the 2016 U.S. presidential election.
The U.S. secretary of defense also expressed concern over Russia's activities in Afghanistan and its interaction with the Taliban militant group.
"We have seen Russian activity vis-a-vis the Taliban," Mattis said. "I am not willing to say at this point if that is manifested into weapons and that sort of thing, but, certainly, what they are up to there in light of their other activities gives us concern."
The comments came after U.S. General Curtis Scaparrotti, NATO's supreme allied commander in Europe, told a U.S. Senate committee on March 23 that he had seen evidence of increasing Russian efforts to influence the Taliban "and perhaps even to supply" the militant group.
Moscow denies it provides aid to the Taliban, which is fighting the U.S.-backed government and U.S. forces in Afghanistan.
Speaking to reporters in Brussels on March 31, Russia's ambassador to NATO, Aleksandr Grushko, said Russia is in contact with the Taliban to push the group toward national reconciliation and to ensure security of Russian citizens.
"Many countries" maintain contacts with the Taliban, Grushko said, adding that "the consultations we hold, the work we do, we do it with the participation of Afghanistan's central government."
With reporting by AFP, AP, Reuters, TASS, and Interfax