A new military doctrine signed by President Vladimir Putin identified NATO as Russia's number one military threat and raised the possibility of a broader use of precision conventional weapons to deter foreign aggression.

The new doctrine was signed on Friday, and it maintains the provisions of the 2010 edition of the military doctrine regarding the use of nuclear weapons.

The doctrine, which came amid tensions over Ukraine, reflected the Kremlin's readiness to take a stronger posture in response to what it sees as US-led efforts to isolate and weaken Russia.

Russia's relations with the West have plummeted to their lowest level since Cold War times, and NATO cut off ties to Moscow after it annexed Ukraine's Crimean Peninsula in March.

The doctrine says Russia could employ nuclear weapons in retaliation for the use of nuclear or other weapons of mass destruction against the country or its allies, and also in the case of aggression involving conventional weapons that "threatens the very existence'' of the Russian state.

For the first time, the new doctrine says Russia could use precision weapons "as part of strategic deterrent measures", the Associated Press reported.

Examples of precision conventional weapons include ground-to-ground missiles, air- and submarine-launched cruise missiles, guided bombs and artillery shells.

The document does not spell out when and how Moscow could resort to such weapons.

NATO 'poses no threat'

The doctrine places "a build-up of NATO military potential and its empowerment with global functions implemented in violation of international law, the expansion of NATO's military infrastructure to the Russian borders'' atop the list of military threats to Russia.

NATO spokeswoman Oana Lungescu responded by saying in a statement that the alliance "poses no threat to Russia or to any nation".

"Any steps taken by NATO to ensure the security of its members are clearly defensive in nature, proportionate and in compliance with international law.

"In fact, it is Russia's actions, including currently in Ukraine, which are breaking international law and undermining European security," she said.

The doctrine also mentions the need to protect Russia's interest in the Arctic, where the global competition for its vast oil and other resources has been heating up as the Arctic ice melts.