Eight northern European nations agreed Wednesday to step up cooperation to counter an increase in Moscow's military activity that has included a tripling of NATO intercepts of Russian jets this year.
Defense ministers from Nordic and Baltic states and Britain agreed to do more to share intelligence and widen cross-border air force training in the Nordic region after the crisis in Ukraine raised East-West tensions.
British Defense Secretary Michael Fallon said Russia was "regularly flouting the rules of international aviation" and intimidating nations by sending jets as far as Ireland and Portugal.
"NATO has recorded over 100 intercepts so far this year, three times as many as in 2013 and the year is not yet finished," he told a news conference. "We will not allow Russia to continue to invade our airspace."
He said Britain was offering to extend a mission by its Typhoon jets to help police Baltic airspace in 2015 and that the northern European nations wanted to share more intelligence and data about Russian military activity.
Norwegian Defense Minister Inger Eriksen Søreide said all the ministers "agree that Russia's actions [in Ukraine] are totally unacceptable and violate fundamental principles of international law."
She said there had been more Russian military activity in the Arctic and the Baltic Sea, including more planes in different flight formations from previous years. "We do not see a direct military threat from Russia," she added.
Among the new plans, she said that existing air force training cooperation between Finland, Sweden and Norway would be extended to Denmark and cover all Nordic airspace. NATO would work to help Baltic nations improve their military capacities.
Baltic nations feel especially vulnerable after Russia annexed Crimea from Ukraine in March. "Military aggression against Ukraine was foreseen by very few policymakers. The warning time has been reduced to virtually zero," Estonian Defense Minister Sven Mikser said.
President Vladimir Putin has committed to reinvigorating Russia's armed forces, which had been undermined by the economic troubles that followed the collapse of the Soviet Union. He denies any aggression towards NATO.
Last week, former Soviet leader Mikhael Gorbachev warned that tensions over Ukraine threatened to cause a new Cold War.
Asked if he agreed with Gorbachev, Fallon said: "We are in a new stage of our relationship with Russia, that is very clear. Russia has stepped outside the framework of international law."