Russia is to alter its military strategy as a result of the Ukraine crisis and Nato's presence in eastern Europe, a top Russian official says.
Mikhail Popov, a Kremlin adviser, said that deteriorating relations with the US and Nato would be reflected in the updated strategy. Nato said on Monday it would boost its presence in eastern Europe to protect its members.
Ukrainian troops are battling pro-Russian rebels in east Ukraine. About 2,600 people have died since fighting began in April.
Ukraine's defence minister on Monday accused Russia of launching a "great war" that could claim tens of thousands of lives - claims dismissed by Russia, which denies actively supporting the rebels.
Mr Popov, deputy secretary of Russia's National Security Council, told Russia's RIA news agency that "the military infrastructure of Nato member states" was "getting closer to [Russian] borders, including via enlargement".
Nato's actions were one of the key "external threats" to Russia, he said. "Nato's planned action... is evidence of the desire of US and Nato leaders to continue their policy of aggravating tensions with Russia", Mr Popov said. There were no details on how the doctrine might change.
Almost on the eve of Nato's summit gathering in Wales, the Russian government has signalled that it will respond to Nato's plans to make preparations to deploy crisis response forces to Eastern Europe, closer to Russia's borders.
Nato insists that while there will be pre-positioned supplies and more exercises in Poland for example, these will not be permanent new bases. But that is not going to cut much ice in Moscow.
The comments by the top Kremlin security adviser Mikhail Popov has signalled that these new Nato deployments, along with missile defence plans and the Ukraine crisis, will play into a review of Russia's own defence planning.
Moscow is getting its retaliation in first with the stage set for worsening tensions between Russia and the Nato alliance.
There are growing questions now as to just how far the Kremlin is prepared to go in seeking to influence the Ukraine fighting on the ground.
