Putin signed a decree to upgrade the Northern Fleet to a military zone from 2021, in charge of some areas northwest of Russia and the Arctic region.

"This decree considers the Northern Fleet as a strategic constituent of the Russian Armed Forces, carrying out the tasks of a military zone," the document signed by President Vladimir Putin is correct.

President Putin approved this document with the aim of "taking measures to protect the integrity and inviolability of Russian territory", the document said.

Before that, Putin signed an ordinance on the administrative and military boundaries of Russia, designating the Northern Fleet as a military zone from the beginning of next year.

The Northern Fleet is a strategic and constituent force of the Russian navy, performing the task of ensuring that strategic nuclear forces at sea are always ready to fight to maintain their nuclear deterrence.

The North Fleet's main base is at Severomorsk, Murmansk province.

The Russian army currently maintains four military zones, including the Western Military Region, the Southern Military Region, the Central Military Region and the Eastern Military Region.