Ukrainians go to the polls on Sunday in the second round of an election to pick the country's next president.
According to opinion polls, politically inexperienced comedian Volodymyr Zelenskiy is set to defeat incumbent rival Petro Poroshenko.
Poll stations are set to open 05:00 GMT and close 12 hours later.
A survey by the Rating pollster shows Zelensky winning 73 per cent of the vote, with Poroshenko getting only 27 per cent.
The winner of Sunday's vote will be elected for a five-year term as president.

Israel and Hezbollah agree to ceasefire
Two trains collide north of London, multiple injuries reported
Meloni says Trump 'totally invented' story that she begged him for photo
US-Iran peace talks in Geneva called off, clouding prospects for lasting truce
Norway imposes near ban on AI in elementary school
