"Congratulations to Volodymyr Zelensky and the people of Ukraine on free and fair elections," Mr Ratas wrote on Twitter on Monday, adding that Estonia would continue to support Ukraine, its territorial integrity, its sovereignty and reforms.

Congratulations to Volodymyr Zelensky and the people of #Ukraine for free and fair elections. Estonia will continue to support Ukraine, its territorial integrity, sovereignity and reforms.

— Jüri Ratas (@ratasjuri) April 22, 2019

Mr Zelensky, a comedian, screenwriter, actor and director, on Sunday scored a landslide victory in the second round of Ukraine's presidential elections, unseating incumbent Petro Poroshenko with 73.2% vs 24.46% at 85.56% reporting. Mr Zelensky led in all electoral districts but Lviv.

An overwhelming majority of the 1,138 Ukrainian voters to cast their votes in Estonia on Sunday supported Mr Zelenksy's candidacy as well.

A total of 822 voters cast their ballot in favour of Mr Zelensky, while another 298 voted in favour of Mr Poroshenko. A total of 17 spoiled paper ballots were cast as well.

Mr Poroshenko conceded defeat on Sunday night already, congratulating his opponent on his landslide victory. The results were "clear," he said, and a reason to "call my opponent and congratulate him."

The outgoing head of state stressed, however, that he would be leaving office but did not intend to leave politics.

According to the latest information, voter turnout in Ukraine totalled 62.07%.