Nelson Mandela's former wife Winnie has arrived at the hospital in South Africa where the former president is being treated for a recurring lung infection.
Their eldest daughter, Zenani, has returned to South Africa from Argentina, where she is the ambassador, to visit her father at the hospital in Pretoria.
Two other children visited on Sunday.
The government said in a statement:
"President Jacob Zuma reiterates his call for South Africa to pray for Madiba and the family during this time." Madiba is Mr Mandela's clan name.
Presidential spokesperson Mac Maharaj said his condition is serious but stable; unchanged since his admission to hospital on Saturday.
Mr Mandela, 94, was admitted to hospital early on Saturday for the third time this year. He is being treated for a lung infection.
The presidency said Mr Mandela had been ill for some days at his home in Johannesburg. He was admitted to hospital after his condition worsened at 1.30am on Saturday.
Mr Mandela served as president from 1994 to 1999. He contracted tuberculosis in the 1980s while imprisoned on Robben Island.