Estonia says it will refuse to recognise Russian passports controversially offered to residents in separatist-controlled eastern Ukraine.
Vladimir Putin earlier this year promised fast-tracked citizenship to anyone living in Ukraine's Donetsk and Luhansk Oblasts.
Russia’s president was accused of attacking Ukraine's sovereignty and endangering a ceasefire in the region.
Estonia’s foreign ministry said it would not recognise Russian passports issued in those areas after April 24, 2019, unless the holder was previously a Russian citizen.
"Granting expedited Russian citizenship to the residents of eastern Ukraine is another attempt to undermine the independence of Ukraine and perpetuate the current unstable security situation in eastern Ukraine,” foreign minister Urmas Reinsalu said in a statement issued on Monday.
“It goes completely against the spirit of the Minsk agreements. Today's decision by Estonia reflects our fundamental condemnation of Russia’s ambitions of this nature.”
Estonia is the first EU member state to take the step, according to state broadcaster, ERR. Worldwide, Canada was the first.
Reinsalu said he believes other EU states could soon follow, adding: “It is our duty to continue to actively support the sovereignty and territorial integrity of Ukraine.”
Estonia has previously decided not to recognise the passports of the Russian Federation issued in Crimea and Sevastopol to local residents after March 18, 2014, if the user of the passport was previously not a Russian citizen.