Finnish and Swedish fighter jets scrambled for the first time on Sept. 24 to intercept supersonic Russian military aircraft flying over the Gulf of Finland, marking a major milestone in Nordic defense cooperation amid heightened tensions with Moscow.

The mission also came one day before Russian President Vladimir Putin dismissed European warnings about the threat from Moscow in the region and mocked Estonia's new defense minister over the Baltic state's preparations for a potential Russian attack.

Finnish F/A-18 Hornets and Swedish JAS 39 Gripens were scrambled after Russian aircraft were detected in the international airspace, according to the Russia's invasion of Ukraine in 2022, Reuters has reported.

NATO said in June that it was enhancing protection of its eastern members in the cyber and space domains while helping countries build resilience against what it describes as hostile Russian actions, including cyberattacks, sabotage and airspace violations.

NATO says its military activities along the eastern flank are entirely defensive and that it is "ready, willing and able to defend every Ally."

The alliance has said an attack against any member would be met with a "resounding response."

NATO Secretary General Mark Rutte recently underscored Washington's role in the alliance during a visit to Iowa, telling The Associated Press that Putin "knows that the United States and Europe are totally intertwined."

"We have to make sure that we are prepared, we are strong, and he knows it," Rutte said.

"And if he does anything silly, he knows our reaction will be tough," he warned.

European intelligence officials said Sept. 24 that Russia could test NATO's defenses.

Denmark's Defense Intelligence Service assessed the risk of a limited Russian military attack against a NATO country in the coming months as "low but growing" and said Moscow is expected to intensify its hybrid campaign against NATO and the West.

The service said in a statement that a full-scale Russian invasion of a NATO member remains highly unlikely but can no longer be ruled out.