The first of 800 UK troops have arrived in Estonia as part of a Nato plan to deter Russian aggression in the Baltic.
Some 120 soldiers from the 5th Battalion The Rifles landed at the Amari air base, 25 miles south-west of the capital Tallinn.
They were welcomed by Estonia’s defence minister Margus Tsahkna on their arrival from RAF Brize Norton in Oxfordshire on Friday.
The troops are due to be stationed in the country in one of the biggest deployments to Eastern Europe since the Cold War.
The first group will set up a UK headquarters in the country to prepare for the others’ arrival next month.
Along with French and Danish forces they will provide “a proportionate, defensive, and combat capable force to defend our Nato ally and deter any form of hostile activity against the Alliance”, the Ministry of Defence said.
Britain is taking a leading role in the Estonia Battlegroup while other Nato members are deploying forces to Latvia, Lithuania and Poland as part of Nato’s Enhanced Forward Presence battalion.
Around 300 UK vehicles have also left the UK this week by ferry headed for Estonia, including Challenger 2 tanks, Warrior infantry fighting vehicles, and AS90 self-propelled artillery pieces.
The deployment comes as Nato grows increasingly concerned about Russian aggression in Eastern Europe.
Since the annexation of Crimea and the ongoing conflict on the Donbass region of Ukraine many former Iron Curtain states fear encroachment from their former imperial master.
In January, German and Belgian forces arrived in Lithuania near the Russian enclave of Kaliningrad to help it bolster its defences in case of an invasion.
Prime Minister Theresa May confirmed the UK would come to the aid of allies such as Estonia or Lithuania in the event they were invaded by Russia and took the country’s commitment to Nato seriously.
Under the terms of Article 5 of Nato, if one member state is invaded all the other nations are obliged to come to their aid.
There are growing fears about the commitment of Nato’s largest military power, the US, after Donald Trump suggested he may not come to an ally’s defence unless they contribute more to the organisation’s budget.
He later vowed “strong support” for Nato during his first visit to the headquarters of US Central Command in Florida in February.
Nato guidelines say member states should spend at least 2 per cent of their GDP on defence but only five of the 28 in the alliance – the UK, Greece, Poland, US and Estonia – currently meet the target.
Additional reporting by PA