Burundi's foreign ministry says the country's newly-elected president, Évariste Ndayishimiye, will be sworn in on Thursday - two months earlier than planned.
The fast-tracked ceremony follows the death last week of the incumbent, Pierre Nkurunziza.
In a letter, the foreign ministry invited diplomats and foreign organisations to attend the inauguration in the capital, Gitega.
Mr Ndayishimiye is a former Hutu rebel and army general, like his predecessor.
He received the backing of Mr Nkurunziza before winning the presidential election in May.
He had been due to be sworn in August, but the Constitutional Court brought forward the ceremony following the death of the president.