This is a recurring Kremlin narrative about the belligerent West and NATO attempting to encircle and weaken Russia.
NATO’s essential and enduring purpose is to safeguard the freedom and security of all its members by political and military means. Collective defence is at the heart of the Alliance and creates a spirit of solidarity and cohesion among its members.
NATO now focuses on countering new security threats by utilising collective defence, managing crisis situations and encouraging cooperative security, as outlined in the 2010 Strategic Concept.
NATO is not a threat to Russia. NATO's official policy towards Russia was most recently articulated by the heads of state and government of the Alliance at the Warsaw Summit in July 2016. They stated that "the Alliance does not seek confrontation and poses no threat to Russia. But we cannot and will not compromise on the principles on which our Alliance and security in Europe and North America rest".