Ukrainian comedian Volodymyr Zelensky will formally become the country's new president at a ceremony in the capital, Kiev, on Monday.
Mr Zelensky scored a landslide victory in last month's presidential election.
He ousted incumbent Petro Poroshenko who had been in power since 2014.
Mr Zelensky has promised to tackle corruption and bring an end to the war with Russian-backed rebels in the east.
Mr Zelensky starred in the long-running satirical drama Servant of the People in which his character accidentally becomes Ukraine's president.
He plays a teacher who is elected after his expletive-laden rant about corruption goes viral on social media.