British and German pilots are set to conduct joint air policing missions in Estonia for the first time.
The UK is preparing to take over from Germany as leader of the Nato mission in Estonia, which borders Russia.
UK Defence Secretary Ben Wallace has praised the demonstration of Nato unity, in which Typhoon jets for the Royal Air Force and its German counterpart will take part in “integrated” missions.
The Ministry of Defence said about 300 RAF personnel would soon arrive in Estonia. The UK is to lead the Nato mission for four months from April.
The invasion of Ukraine has brought concerns in border states, including Estonia, about Russian President Vladimir Putin’s ambitions and his next steps.
Details of the new Nato mission come after Estonian Prime Minister Kaja Kallas's comfortable win by a large majority in the general election on Sunday.
The politician, who has become popular at home and abroad for her unwavering support for Ukraine, outperformed polls.
Her victory provides a strong mandate for her pledge to maintain Estonia’s transatlantic course as a committed member of the EU and Nato.
“Our RAF personnel in Estonia are undertaking a vital role, ensuring the security of Europe’s skies and bolstering Nato’s presence in eastern Europe," Mr Wallace said.
“Joint operations of this kind demonstrate the strength and unity of the Nato alliance and our shared resolve to maintain peace and security across the region.”
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Scott Maccoll, commanding officer of the 140 Expeditionary Air Wing, said: “Today marks a great first for our two Air Forces.
"We have been working together for some time and the level of co-operation has now reached a new level.
“It continues to be an absolute pleasure to work with our German allies on all aspects of our mission, from maintenance and operation of the jets to planning and logistic activities.”
“What better way to demonstrate the strength and unity of the Nato alliance than through successful, shared operations such as this?”
The ministry said that the mission formed part of the UK’s commitment to Nato member Estonia.
“Working together with our allies from the Royal Air Force in a live mission is what we have been looking forward to since we started this mission," said Lt Col Christoph Hachmeister, the German detachment commander.
“Now we can demonstrate interoperability in these difficult times to protect our Baltic partners and Nato’s eastern flank.
“The many years of good practice in working together will be the baseline for a successful co=-operation.”
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Labour's shadow defence secretary John Healey said his party’s commitment to Nato co-operation with allies such as Germany is “unshakeable”, as he warned of the danger of cuts to defence projects.
“Our RAF pilots will conduct these welcome exercises with total professionalism," Mr Healey said.
"But the Conservatives’ mismanagement of defence projects such as Wedgetails and cuts to military transport planes are leaving the UK’s Nato obligations in doubt.
“Labour in government would apply a ‘Nato test’ to major defence programmes to ensure our Nato commitments are fulfilled.”