Estonian Prime Minister Taavi Roivas urged NATO to establish a permanent presence in the Baltic state in response to Russia's actions in Ukraine, telling his allies to "open your eyes and stay awake".
The Western alliance has tripled the number of fighter jets based in the Baltics as part of measures to beef up its defenses in eastern Europe following Russia's annexation of Crimea.
The events in eastern Ukraine, where Russian-speaking insurgents using sophisticated weapons threaten to split the country, have put the whole former Soviet bloc region on alert and eager for NATO reassurance.
Asked if he would like to see a permanent mission in Estonia, Roivas told Reuters in an interview on Friday: "Estonia, Latvia, Lithuania, Poland and Romania are the border states, and it is only logical that air policing and air defense for example are present on the borders."
NATO's top military commander, U.S. Air Force General Philip Breedlove, said last month that NATO would have to consider permanently stationing troops in eastern Europe.
But some NATO allies argue that permanent basing of large numbers of troops in the east is too expensive, not a military necessity and needlessly provocative to Moscow.
Asked about the risk of antagonizing Moscow further, Riovas said: "Russia has done everything to break all agreements and has been very aggressive... we have the alarm bell ringing in Ukraine and I really believe that now is the time to open your eyes and stay awake."
NATO has arranged a number of short-term army, air force and naval rotations in Eastern Europe, but these are due to finish at the end of this year.
Long-term plans include training drills that will consistently keep about 100 U.S. elite troops on the ground at any one time in NATO states close to Russia, with teams working in several countries, a U.S. official said.