About 150 British Army and Royal Air Force personnel have taken part in a joint “high-readiness exercise” in Finland alongside US and Finnish armed forces.
The UK Ministry of Defence said the four-day Exercise Vigilant Fox involved a combined 750 troops from all three countries.
The joint exercise comes after Nato signed an accession protocol with Finland earlier this month, as the ratification process that will allow the Scandinavian country to join the alliance continues.
Finland and Sweden both confirmed their intention to join Nato following Russia’s invasion of Ukraine.
Helsinki signed a mutual security assurance declaration with the UK in May and it is also a member of the 10-nation UK-led Joint Expeditionary Force.
The ministry said British troops based in Estonia as part of the British Army’s Project Unified Stance were flown to Finland in Royal Air Force Chinook helicopters as part of the exercise.
Minister of State for the Armed Forces James Heappey said: “Exercise Vigilant Fox has demonstrated the strength and interoperability of our armed forces with our US and Finnish allies and reaffirms our commitment to the defence and security of the Baltic Sea region.”
Wing Commander Stephen Boyle, the UK defence attache in Helsinki, said: “Our soldiers, sailors and aviators have received a warm welcome in Finland over the last few months.
“Exercise Vigilant Fox is the latest activity in an ongoing series of events across the domains. As Finland moves towards full Nato membership, we will continue to seek opportunities like this to show solidarity with Finland, learn from each other and improve our ability to operate together.”