Nelson Mandela remains in a critical condition but is responding to treatment, the South Africa presidency said on Wednesday. President Jacob Zuma visited Mandela in a Pretoria hospital, where he has been hospitalized since June 8 for a lung infection. "We are encouraged that Madiba is responding to treatment and urge the public to continue providing support and showering him with love which gives him and the family strength," said Zuma, using Mandela's clan name.