Boris Johnson warned Sweden and Finland must be free to join NATO without 'fear of retaliation' as he visited the countries to sign historic security assurance declarations today.
The PM sent a stark message to Vladimir Putin as he inked pledges to 'bolster military ties' and support both countries should they come under attack.
Speaking alongside Swedish counterpart Magdalena Andersson at her Harpsund country residence, Mr Johnson said it was a matter for the country's people whether to apply for membership of the military alliance.
But he insisted: 'Sovereign nations must be free to make those decisions without fear or influence or fear of retaliation.'
Mr Johnson set out a UK commitment to come to the country's aid in the event of a crisis, saying if help was requested 'we will provide it'.
