NATO has announced it intends to increase its military presence in eastern Europe with the formation of a new multinational force of up to 4,000 troops in Romania.
In a speech to a session of the NATO Parliamentary Assembly in Bucharest, NATO Secretary General Jens Stoltenberg said the deployment is a response to Russia’s aggressive actions in Ukraine and its military build-up in the region.
"Our deployments are a direct response to Russia’s aggressive actions in Ukraine"
In September Russia staged it biggest military exercise since the annexation of Crimea in 2014.
Russia's defence ministry said about 12,700 troops, along with armoured units, warships and aircraft took part in Zapad 2017 with Belarus.
NATO insisted the number of troops was much higher.
Earlier this year NATO deployed four multinational battlegroups containing around 1,100 troops in each unit to Poland, Estonia, Latvia and Lithuania, which border Belarus and Russia.
A move Stoltenberg said was sending a clear message to Russia.
"NATO’s actions are defensive, proportionate and entirely in line with our international commitments".
NATO has also increased air patrols in the region with Britain deploying fighter planes to Romania.
Canada is already patrolling the airspace, while Italy patrols over Bulgaria.
Russia has accused NATO of trying to encircle the country and threatening stability in eastern Europe, which NATO has denied.