Officials at Russia's foreign and defense ministries did not immediately respond to a request for comment.

Kyiv, Washington and Western capitals have raised concerns about a Russian troop buildup near Ukraine and the possibility of an invasion.

U.S. and Russian officials convened for talks in Geneva on Monday to try to deescalate the crisis.

Moscow has denied planning an attack and accused Ukraine and NATO of fomenting tensions, demanding that the US-led alliance guarantees it will not grant Kiev membership.