Russia has sent follow-up questions rather than a response to the United States in their exchange on Moscow's demands for security guarantees, a senior Russian diplomat was quoted as saying on Tuesday.
A State Department spokesperson said on Monday the United States has received a written follow-up from Russia on the matter.
But a senior diplomatic source told Russia's state news agency RIA the letter contained questions from Foreign Minister Sergei Lavrov, also sent to other NATO members, on how Moscow's counterparts understood the "indivisibility of security" principle.
Moscow was still working on an actual response to Washington's counter-proposals, the source said.
Washington and Brussels replied last week to Moscow's demands for legally binding security guarantees amid a standoff over Ukraine's plans to join NATO.
Russian President Vladimir Putin said last week they had not addressed Moscow's main security demands but Russia was ready to keep talking.
(Reporting by Maxim Rodionov; Writing by Olzhas Auyezov; Editing by Andrew Heavens)