South Africans continue to gather outside the hospital in Pretoria where anti-apartheid icon Nelson Mandela remains in critical condition.
The South African president's office said Thursday Mandela's condition was "critical, but now stable" after improving overnight.
Earlier, Mandela's daughter Makaziwe said her father did not look good, but was still opening his eyes and responding to touch.
Dozens of well-wishers held a candlelight vigil throughout the night, delivering flowers and messages of support for the 94-year-old leader.
U.S. President Barack Obama, who visits the country Friday, said his thoughts and prayers are with Mandela, the country's first black president.
White House officials say they will leave it up to the Mandela family to decide whether President Obama will visit Mandela. The U.S. leader is visiting South Africa as part of his week-long visit to the continent.
Mandela has been at Pretoria's Mediclinic Heart Hospital since he was rushed there June 8 for a recurring lung infection.
On Tuesday, Cape Town Archbishop Thabo Makgoba offered a prayer that Mandela be granted a "peaceful, perfect end."