Putin has also declared a partial military mobilisation, with 300,000 reservists to be called up as the Kremlin tries to retake ground in the face of a counter-attack by Ukrainian forces.
And he said “it’s not a bluff” when he vowed that Russia would use its weapons of mass destruction if its territory was threatened, accusing the West of "nuclear blackmail.”
But what exactly does the Russian president mean when he says ‘the West’, and what relevance do his threats have to the UK?
Here is everything you need to know.
What did Putin say?
In a speech, the Russian president accused the West of “nuclear blackmail,” claiming that “high-ranking representatives of the leading Nato states” had discussed unleashing weapons of mass destruction against Russia.
And he added: “To those who allow themselves such statements regarding Russia, I want to remind you that our country also has various means of destruction, and for separate components and more modern than those of Nato countries, and when the territorial integrity of our country is threatened, to protect Russia and our people, we will certainly use all the means at our disposal.”
What does Putin mean by ‘the West’?
Historically, the concept of a culturally “Western” part of the planet stems from the doctrinal separation between the Western Roman Catholic and Eastern Orthodox Churches.
But it has morphed from a geographical concept to a socio-political concept endowed with notions of progress and modernity, driven by the advancement of communication and transportation technologies effectively ‘shortening’ the distance between the shores of the Atlantic Ocean.
By the mid-20th century, Western culture was exported around the globe via mass media like film, television and popular music, and played a critical role in modern globalisation.
Depending on the context in which the term is used, “the West” can refer to a variety of regions, nations and states, but it most commonly refers to the majority of Europe (including the UK), North America and Oceania.
One definition in modern use suggests the Western world refers to Europe and countries where certain European ethnic groups have had a major presence since the 15th century - the ‘Age of Discovery’.
That would explain why Australia and New Zealand - BOTH firmly placed in the Earth’s Eastern hemisphere - are considered part of the West; significant British influence derived from the colonisation of British explorers and the immigration of Europeans in the 20th century has grounded both countries to the Western world politically and culturally.
But there is no hard and fast rule on which regions are considered part of the West, and muddying the waters further, Russia has at times been viewed as part of it, and at others opposed to it, depending on the context and historical period.
Could nuclear missiles come to the UK?
Since the UK is certainly included in Putin’s current definition of the West, the latest escalation in rhetoric will have many Brits anxious at the thought of nuclear conflict making its way to our shores.
It is “possible” that Russia could launch nuclear missiles at London, a former adviser to Russian President Vladimir Putin has claimed.
On whether nuclear missiles could come to London, Russian political scientist Sergei Markov told BBC Radio 4’s Today programme “yes, it is possible”.
He said the situation could be created “if Great Britain continues to be aggressor against Russia, if Prime Minister of Great Britain Liz Truss still has plans to destroy Russia”.
He added: “People in London should understand that this threat comes from Liz Truss, who is the aggressor. Stop the war against Russia on the Ukrainian territory.”
Adding further to the unnerving rhetoric, a former adviser to Putin has also suggested the Russian leader would be ready to use nuclear weapons against nations such as the UK, saying it “could kill a lot of people in the Western countries”.
Political scientist Sergei Markov said: “This nuclear war could be a result of the crazy behaviour of the president of the United States Joe Biden and prime ministers of Great Britain Boris Johnson and Liz Truss.”
But Foreign Office minister Gillian Keegan has said discussions will continue to seek a diplomatic solution to the Ukraine war, and was asked whether such a solution could still happen and whether channels are open between Moscow and London.
The Chichester MP told BBC Breakfast: “There will always be discussions that will be going on either via Ukraine or other countries as well. or directly, so we will continue to urge calm and we will continue to have those discussions where possible.”