NATO Secretary Jens Stoltenberg is calling for European powers to "modernize" security protocols in the region as tensions grow between the alliance and Russia.

Stoltenberg, the top official of the alliance said the continent's security atmosphere has destabilized in the face of Russian militarism in a recent editorial, adding issues like the tensions between Moscow and the Turkish government over the shooting down of a Russian fighter should be resolved diplomatically. The NATO chief also called for the alliance to strengthen its security capabilities.

"This is not a new Cold War. But it is a wake-up call," Stoltenberg wrote. "The reality is that the rule-book of European security is out of date. We need to modernise it to reflect today's reality and re-engage Russia."

The Secretary General's call for strength and diplomacy come nearly a month after the alliance concluded its largest military exercise in over a decade. Trident Juncture 2015, which began on October 19, involved around 36,000 troops from over 30 countries. However, Stoltenberg pointed out several of Russia's military exercises involved over 150,000 troops, with some appearing to simulate nuclear attacks.

Despite the size and scope of the exercises, Stoltenberg affirmed Russia is within its rights to strengthen its own military capabilities. However, the Secretary General is asking Moscow to be more transparent on their activities and intentions.

"Military training and exercise is part and parcel of every nation's right," Stoltenberg added. "However, unlike Russia, we publish our exercise schedule, and we invite observers, including from Russia, to attend. This stands in stark contrast with Russia's calculated unpredictability and lack of transparency."

Russian observers were invited to attend part of Trident Juncture 2015.