MOSCOW - Russia identified NATO as the nation's No. 1 military threat and raised the possibility of a broader use of precision conventional weapons to deter foreign aggression under a new military doctrine signed by President Vladimir Putin on Friday.

NATO flatly denied it is a threat to Russia, and accused Moscow of undermining European security.

The new doctrine, which comes amid tensions over Ukraine, reflected the Kremlin's readiness to take a stronger posture in response to what it sees as U.S.-led efforts to isolate and weaken Russia. The paper maintains the provisions of the previous, 2010 edition of the military doctrine regarding the use of nuclear weapons.

It 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.

But for the first time, the new doctrine says Russia could use precision weapons "as part of strategic deterrent measures." The document does not spell out when and how Moscow could resort to such weapons.

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

Among other things, the paper mentions the need to protect Russia's interests in the Arctic, where the global competition for its vast oil and other resources has been heating up as the Arctic ice melts.

Russia has relied heavily on its nuclear deterrent and lagged far behind the U.S. and its NATO allies in the development of precision conventional weapons. However, it has recently sped up its military modernization, buying large numbers of new weapons and boosting military drills. It has also sharply increased air patrols over the Baltics.

Russia flexed its muscle this month by airlifting state-of-the art Iskander missiles to its westernmost Kaliningrad exclave bordering NATO members Poland and Lithuania. The missiles were pulled back to their home base after the drills, but the deployment clearly served as a demonstration of the military's readiness to quickly raise the ante in a crisis.