NATO must ensure Vladimir Putin suffers a 'huge personal cost' if he dares to expand his Ukrainian invasion to other nations, the Royal Navy chief warned.
Admiral Sir Ben Key, the First Sea Lord, said it is key for NATO nations to 'contain' the war in Ukraine so that it does not 'accelerate away from us'.
His warning comes as there is mounting fear Putin could expand his invasion into Moldova's breakaway region of Transnistria, an unrecognised Moscow-backed sliver of land bordering southwestern Ukraine.
There are also fears of Russian interference in Sweden after the country announced it is considering applying for NATO membership, prompting NATO Secretary General Jens Stoltenberg to say the alliance could heighten its presence around the nation to protect it from any aggression.
Sir Ben told The Daily Telegraph: 'The lessons of history would say that we are in a particularly fragile moment right now.
'[This] is why it's really important that while the support we are giving to Ukraine at the moment is to enable them, we have to show a robust a resilient posture across the rest of the contact line with Russia, wherever that is, at sea, in the air, the rest of the NATO landmass, so that Mr Putin understands that this is not something that he can broaden without a huge cost to him and Russia.'
Admiral Sir Ben Key, the First Sea Lord, said it is key for NATO nations to 'contain' the war in Ukraine so that it does not 'accelerate away from us'
Sir Ben, who led the UK's airlift of British citizens and Afghans from Kabul after the Taliban takeover, accused Putin of committing an 'egregious wrong' against Ukraine.
The First Sea Lord urged the UK to continue to send weapons to Ukraine so that their troops can 'defend their territory, their homeland and their people'.
But Sir Ben said that whilst the aim of doing so is for Putin to 'desist' from his invasion, he admitted that outcome is 'a long way away at the moment'.
Sir Ben also said it was imperative for the navies of NATO nations must remain a deterrent position to 'counter Putin's actions and dissuade him from doing more'.
'We represent a threat,' the Navy chief said. 'The Russians effectively tried to exclude any other ships from operating in the northern part of the Black Sea, and the Ukrainians demonstrated that was not something that they could do freely.'
Sir Ben warned 'ships become valid targets' during war, and the UK must be prepared for any attacks.
'That requires for our posture to be correct, for our capabilities to be properly aligned, for us to be modernising and adapting to seeing what others can do and what technology opportunity offers us,' he said.
Sir Ben, who led the UK's airlift of British citizens and Afghans from Kabul after the Taliban takeover, accused Putin of committing an 'egregious wrong' against Ukraine. Pictured: Anna Shevchenko, 35, waters the few flowers that survived in the garden of her destroyed home in Irpin, near Kyiv, on Tuesday
His comments comes as NATO chief Jens Stoltenberg said that the alliance must guarantee Sweden's security if it decides to join NATO.
'We must remember that from the moment Sweden potentially applies, and NATO says that it wants Sweden to join, there is a very strong NATO obligation to guarantee Sweden's security', Stoltenberg told Swedish public television SVT.
'We have several ways of
