The International Criminal Court (ICC) has called on South Africa to arrest Sudanese President Omar al-Bashir who is in the country for an African Union (AU) summit.
Mr Bashir is wanted for war crimes over the conflict in Darfur.
An ICC statement said South Africa should “spare no effort” in detaining him.
But instead he was welcomed by South African officials on his arrival in Johannesburg, SABC tweeted.
Sudan’s Suna news agency said he was accompanied by the foreign minister and other top Sudanese officials.
There are tensions between the ICC and the AU, with some on the continent accusing the court of unfairly targeting Africans.
The AU has previously urged the ICC to stop proceedings against sitting leaders.
The warrants against Mr Bashir, who denies the allegations, have severely restricted his overseas travel.
He has, however, visited friendly states in Africa and the Middle East.
The ICC has no police force and relies on member states to carry out arrests.
As a signatory to the Rome Statute that established the ICC, South Africa is obliged to arrest President Bashir if he sets foot in the country, but correspondents say this is unlikely to happen.
The AU has previously refused to co-operate with the ICC, accusing it of bias against African leaders.
Sidiki Kaba, president of the assembly of states to the ICC, expressed “deep concern about the negative consequences for the court” if South Africa refused to comply with its obligations to carry out the arrest.
Human rights organisations and South Africa’s main opposition party have also called for Mr Bashir’s arrest.
Darfur has been in conflict since 2003, when rebels took up arms against the government. The UN says more than 300,000 people have died, mostly from disease.
The ICC has ended an investigation into war crimes in the region, but the warrants against Mr Bashir remain outstanding. The court accuses him of crimes against humanity, war crimes and genocide.
The official theme of the AU summit is the “Year of Women’s Empowerment and Development”.
But the political turmoil in Burundi, crisis in South Sudan and the recent spate of xenophobic attacks in South Africa are also likely to feature heavily.
The AU’s agenda: Nomsa Maseko, BBC News, Johannesburg
African Union meetings are often criticised for avoiding burning issues that affect the continent, and this year’s summit is not expected to be any different. Analysts say discussions will be held, but outcome will be vague.
The packed agenda is expected to focus on violence in Burundi, the crisis in South Sudan, Nigeria’s fight against Boko Haram, and terror threats by al-Shabab in East Africa.
South Africa stepped in to host the summit at the last minute because of terror threats in Chad.
But the recent xenophobic violence in Johannesburg and Durban have left the hosts embarrassed.
Zimbabwe, Mozambique and Nigeria lashed out at President Jacob Zuma’s government for the attacks.