The United States on Friday dismissed as public posturing Russian complaints about Nato's enlargement onto former Soviet soil and said there was no sense of a crisis between the Cold War foes.
Russia said this week that it would "respond accordingly" to Nato warplanes patrolling on its frontiers after the three Baltic states join the US-led defence bloc next Monday.
Its defence minister, Sergei Ivanov, followed up with a warning that Moscow might revise its Nato-friendly military stance if the alliance did not drop its "offensive military doctrine".
"While you may be reading things or people may be saying things in the press, the discussions that we are having on a Nato basis with Russia have been constructive and straightforward," US Ambassador to Nato Nicholas Burns said.
"There is no sense of a crisis at all between Nato and Russia over enlargement," he told a news conference.
The three Baltic states of Estonia, Latvia and Lithuania - formerly Soviet republics - will join Bulgaria, Romania, Slovakia and Slovenia in Washington on Monday for an accession ceremony taking the military alliance's membership to 26.