West's support for Ukraine risks 'full-scale nuclear war,' top Russian official warns

The Kremlin responded to Finland's announcement in favour of joining NATO on Thursday, saying the decision is a radical change in the country's foreign policy and that Finnish entry into NATO is "definitely" a threat to Russia. 

In response to the West sending arms supplies to Ukraine, top Russian official Dmitry Medvedev said there is a growing threat of the fighting in Ukraine spilling into a direct conflict between Russia and NATO.

Medvedev, who is the deputy head of Russia's Security Council, said NATO's support for Ukraine has "increased the probability that an ongoing proxy war will turn into an open and direct conflict between NATO and Russia."

He also said that "there is always a risk of such conflict turning into a full-scale nuclear war, a scenario that will be catastrophic for all."

WATCH | NATO special forces carry out training drills in eastern Europe:

In a messaging app commentary, Medvedev urged the United States and its allies to think about the possible consequences of their actions and "not to choke on their own saliva in the paroxysms of Russophobia."

Since Russia has refocused its invasion in the eastern Donbas region, Ukraine has been able to recapture several towns and villages in the country's northeast, according to British intelligence.

Britain's military said Russia's change in approach left its remaining troops around the city of Kharkiv "vulnerable to the mobile, and highly motivated, Ukrainian counter-attacking force."

Kharkiv, Ukraine's second-largest city, suffered heavy Russian bombardment during the war as Russia sought to encircle it. But the U.K. said in an intelligence update on social media that "it has reportedly withdrawn units from the region to reorganize and replenish its forces following heavy losses."

It said that withdrawal was "a tacit recognition of Russia's inability to capture key Ukrainian cities where they expected limited resistance from the population."

Meanwhile on Thursday, Russian President Vladimir Putin reaffirmed his determination to wrest separatist-held territory from Ukraine in a congratulatory message to the head of the self-proclaimed Luhansk People's Republic in Eastern Ukraine.

In a statement released by the Kremlin, Putin said: "I am sure that through our joint efforts we will defend the independence, sovereignty and territorial integrity" of the Luhansk republic.

The head of the Luhansk self-proclaimed republic, Leonid Pasechnik, said it would never return to Ukrainian control and that most of its residents want it to become part of Russia.

Ukraine's Foreign Ministry has accused Russia of stealing the country's grain and trying to sell some of it on global markets.