Lt. Gen. John Mead, deputy commander of NATO's Allied Joint Force Command in Brunssum, Netherlands, made the remarks in an interview published on Monday by Estonian outlet ERR News.
Mead, a British officer, said Estonia and Latvia lack "geographic strategic depth," the distance between a potential frontline and key national centres, which complicates logistics.
Still, he said Baltic security had improved significantly since NATO adopted its deterrence and defence strategy for the Euro-Atlantic region.
He called for regular military exercises to ensure troops could operate effectively if needed.
Asked whether Russia might pose a renewed threat if fighting in Ukraine were to end, Mead said such scenarios were already factored into NATO's planning.
About 10,000 NATO troops are currently stationed across the Baltic states, with room for further expansion.
Canada leads a multinational brigade in Latvia; Germany anchors a battlegroup in Lithuania; and Britain leads NATO's forward land force in Estonia.
Allied air forces also rotate through the region under NATO's Baltic air defence mission.
(jh/gs)
Source: PAP