Cyril Ramaphosa has become South Africa’s president a day after embattled leader Jacob Zuma resigned.
He was the only candidate nominated by parliament, which is dominated by his African National Congress. MPs broke into song at the announcement.
In his first presidential speech, Mr. Ramaphosa, 65, said he would tackle the corruption which allegedly became widespread under Mr. Zuma.
The ANC had told Mr. Zuma to step down or face a vote of no-confidence.
Mr. Zuma faces numerous corruption allegations but denies any wrongdoing.
One allegation is that he allowed the wealthy Gupta family, who whom he has personal ties, to wield influence over policy, in an example of “state capture”.
An arrest warrant has been issued for Ajay Gupta, one of the three most prominent Gupta brothers, officials said on Thursday.
This follows a raid by the Hawks, an elite police unit, on their home on Wednesday. The family has denied corruption allegations.
President Ramaphosa told parliament that corruption and state capture were “on our radar screen”.
He is due to deliver a State of the Nation address on Friday. This was delayed last week amid uncertainty about who should deliver it and Mr. Zuma’s reluctance to step down.
Meanwhile, President Muhammadu Buhari has congratulated Ramaphosa on his election today as the fourth president of South Africa.
Buhari also pledged to work with the new president to enhance the cooperation between Africa’s two biggest economies.
A statement issued by senior special assistant to the president on media and publicity, Mr. Garba Shehu said the president also felicitated with the African National Congress (ANC)), and the government and people of South Africa, on the peaceful transfer of power that resulted in the election of President Ramaphosa.
Buhari saluted the leadership and statesmanship of former President Jacob Zuma, and wishes him the best in his future endeavours.
ADDITIONAL REPORT FROM BBC