Siauliai: Britain and France deployed eight fighter jets on Monday to reinforce NATO air patrols over the Baltics as tensions rise with Russia over Ukraine.
Four British Royal Air Force Typhoon fighters landed in Lithuania, while four French Rafale jets touched down in the northern Polish city of Malbork.
British defence minister Philip Hammond said the move would "provide reassurance to our NATO allies in eastern Europe and the Baltic states".
"In the wake of recent events in Ukraine, it is right that NATO takes steps to reaffirm very publicly its commitment to the collective security of its members."
Lieutenant Colonel Simon Hulme of the Royal Air Force, the mission chief in Lithuania, said it will be "business as usual" for the 168 British personnel deployed at the northern Siauliai air base.
"Clearly we are here to reassure our Baltic allies that we are able to protect their air space should it be needed," he told reporters under a sunny sky.
Just five kilometres (three miles) away in the city centre, pensioner Brone Simanauskiene said NATO had allayed some of her concerns about Russia`s intentions.
"We are concerned, but I believe the increased NATO presence will make us safer. I am glad that more jets will arrive," she told AFP before the British jets landed.
Student Ernestas Tuzinas, 22, said NATO must do more to deter Russia from invading Moldova or even the Baltic states, which spent five decades under Soviet occupation until 1991 and joined NATO and the European Union in 2004.
"These are only the first steps. NATO should set up a permanent military base in Lithuania," he told AFP.Before the Ukraine crisis erupted, four jets belonging to NATO allies took turns guarding the airspace above the Baltic states, which have grappled with a shortage of fighter planes.
The United States first increased the number to 10 in March by sending six additional F-15s, and the mission is set to expand further.
Four MiG 29s from Poland will land in Lithuania on Tuesday, while Denmark will contribute four warplanes to be based in Estonia.
Around 70 French military personnel have been deployed to Malbork in support of the four new planes, French military spokesman Colonel Gilles Jaron said.
Britain and France have each also deployed AWACS early-warning aircraft to patrol Polish and Romanian airspace in recent weeks.
NATO announced this month that it would step up its defences in eastern Europe due to the growing crisis in Ukraine and Russia`s absorption of Crimea.
It has also deployed ships in the Baltic Sea and eastern Mediterranean.
The United States announced last week it was deploying 600 airborne troops for exercises in Estonia, Latvia, Lithuania and Poland in a show of solidarity with NATO members bordering Russia.
"NATO has showed it is an effective organisation that does not talk much but takes action," Lieutenant General Arvydas Pocius, Lithuania`s defence chief, told AFP.
He said the deployment of US paratroopers from the 173rd Airborne Brigade was "a special event given the geopolitical context".
"NATO military forces are welcome in Lithuania. Practicing together raises our soldiers` spirits and motivates them."