Petro Poroshenko has been sworn in as president of Ukraine, amid hopes the move can help put an end to deadly fighting in the east of the country, the BBC reports.
The 48-year-old tycoon has been buoyed by messages of support from the West, after his victory in the 25 May poll.
In his speech Mr Poroshenko called for peace, security and unity, saying he did not want war or revenge.
Mr Poroshenko was inaugurated in the presence of dozens of foreign dignitaries – including US Vice-President Joe Biden – in the parliament in the capital Kiev.
Mr Poroshenko, the owner of the Roshen chocolates group, took the oath of office and laid out his programme for ending the crisis, including an offer of early regional elections in the east.
He said: “I don’t want war. I don’t want revenge, despite the huge sacrifice of the Ukrainian people.”