Russian troops with concealed faces and unmarked uniforms have appeared at Estonia's border, echoing tactics used at Ukraine's borders in 2014. Estonian officials called it a "clear danger," while Moscow has dismissed it as routine.

The incident followed a recent string of drone and jet violations of European airspace, to which NATO has responded with its new "Eastern Sentry" mission.

Experts warn Russia aims to keep NATO busy and distract the alliance from aiding Ukraine. However, Estonian Prime Minister Kristen Michal insists support for Ukraine won't waver, saying the best defense is helping Ukraine win faster.