Kallas issued her warning in an interview for The Times. She said that Russia is an aggressor by nature, meaning it will seek to attack where it finds "weakness".
She said that Russia continues, therefore, to represent a serious threat to NATO's eastern flank, including her own country, Estonia.
Estonia intelligence estimates that Russia's recovery from the damage it has sustained from Ukraine will take "3 to 5 years", but this recovery time - as well as the threat it will represent - also depends on the unity of the western alliance.
In an anti-Russian domestic policy move, Kallas has also announced that the Estonian government will cease funding Russian-language education.
24% of the Estonian population are ethnic Russians with a higher percentage being Russian speakers.
Sources: PAP, X
pt