Ukrainian comedian Volodymyr Zelensky will formally become the country’s new president at a ceremony in the capital, Kiev, on Monday.
Mr Zelensky, who has no previous political experience, 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.
It is not clear which issues he will raise in his first speech as leader. The former television actor has said little since his resounding victory on 21 April.
There has been much political wrangling over the timing of Mr Zelensky’s inauguration. He had wanted to hold it on Sunday, a day of mourning for victims of Stalin-era repression in the country.
But parliament disagreed and voted to hold it on Monday morning.
From fiction to reality
Analysis by Jonah Fisher, BBC News, Kiev
Voldymyr Zelensky has done this all before – albeit in a TV series, where he played the part of Ukraine’s president.
At that fictional inauguration he arrived in a taxi and, in his speech, refused to make bold promises. Instead he pledged to do his best for the people of Ukraine.
On Monday it’s happening for real. And it may not be that different.
Mr Zelensky is unlikely to turn up for this inauguration…