Iconic anti-apartheid leader Nelson Mandela remains in critical condition at a hospital in South Africa, where he has been in treatment for a lung infection for more than two weeks.
President Jacob Zuma visited Mandela Sunday evening and was informed that the 94-year-old former president's condition had become critical during the past 24 hours.
"The doctors are doing everything possible to get his condition to improve and are ensuring that Madiba is well-looked after and is comfortable," Zuma said in a statement, using Mandela's clan name. "He is in good hands."
Mandela has had a recurring lung infection and was rushed to the hospital early in the morning on June 8 when his condition deteriorated. Until this week, Zuma has described Mandela's condition as "serious but stable."
Mandela was jailed for 27 years under white racist rule before being released in 1990, according to the Associated Press. He then played a leading role in steering South Africa towards democracy, becoming the country's first black president in all-race elections in 1994.
The former Nobel Laureate has become increasingly frail during the last several years, the AP reported. Mandela's last public appearance was at the 2010 World Cup soccer tournament in South Africa, though he did not deliver an address during the games.
Since contracting tuberculosis during his imprisonment under apartheid, Mandela has been vulnerable to respiratory problems, according to the AP.
Mandela has been hospitalized four times since December, mostly for the ongoing pulmonary condition, according to the Agence France-Presse.
In Washington, the White House acknowledged Mandela's worsening condition, as President Barack Obama prepares to visit South Africa on Wednesday.
"Our thoughts and prayers are with him, his family and the people of South Africa," spokeswoman Caitlin Hayden said, according to NBC News.
In his statement on Monday, Zuma also addressed concerns that surfaced when an ambulance transporting Mandela to the hospital had engine trouble, requiring the former president to be transferred to another ambulance for his 30-mile journey from Johannesburg to Pretoria. Zuma emphasized that Mandela's medical condition was not compromised.
"There were seven doctors in the convoy who were in full control of the situation throughout the period," Zuma said in the statement. "He had expert medical care."
As Mandela's condition has deteriorated during the last few days, South Africans have become increasingly anxious and have been holding vigils outside his hospital, according to CNN.
Supporters have left flowers, cards and balloons outside the gate of the Pretoria hospital where Mandela remains.
"All we do every day is take one day at a time and pray to the good Lord," Mandela's daughter Makaziwe told CNN. "All I pray for as a daughter is that the transition is smooth ... He is at peace with himself. He has given so much to the world."