Ukraine's Petro Poroshenko takes presidential oath in Kiev

Petro Poroshenko has been sworn in as president of Ukraine, amid hopes the move can help put an end to fighting in the east of the country.

In his oath, he promised to commit himself to ''guarding the sovereignty and independence of Ukraine''.

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.