CAPE TOWN - Former South African president Nelson Mandela spends his 20th day in hospital on Thursday amid reports that his condition is worsening.

Only through a miracle, could Mandela make it through, his family told media.

Traditional leader and African National Congress (ANC) MP Phathekile Holomisa said in a statement published by the Eyewitness News that the Mandela family are hoping for a "miracle" to help the much-loved former president.

Madiba's fate is in God's hands, said Holomisa, a longtime friend of Mandela.

"The Mandela family wish a miracle would happen that he recovers, but at the same time they are aware that there's a limit to the miracles you can have," Holomisa said.

Meanwhile, a member of Mandela's family confirmed that the former president was on life support. But it remains unknown what kind of medical instrument is used.

South African President Jacob Zuma cancelled his scheduled visit to Mozambique after visiting Mandela on Wednesday night.

Zuma found Mandela to be still in a critical condition, the Presidency said in a statement.

"President Zuma has decided to cancel his visit to Maputo, Mozambique on June 27, where he was due to attend a Southern African Development Community (SADC) summit regional infrastructure investment conference," the Presidency said.

Mandela, who was admitted to a Pretoria hospital on June 8, has been in a critical condition since Sunday.

A sombre mood prevailed in the country. South Africans interviewed by Xinhua say they hope for the best but have to prepare for the worst.

"We all love him but there is nothing we can do. Look at what is happening (at the hospital). We are expressing our love to him. We can't stop anything, but nothing can stop us to love him," Pheko Mawewe, a member of the ruling African National Congress (ANC) Youth League, said.

"It's time we allow him to rest in peace. Yes, we love him, but considering his age and his condition let's accept that anything can happen now," 73-year-old Anti-apartheid struggle activist William Moshanyana said.

Tribute continued to pour in for Mandela, with UN Secretary General Ban Ki-moon joining the growing number of well-wishers.

The whole world is praying for Mandiba, Ban said.

"I know our thoughts and prayers are with Nelson Mandela, his family and loved ones, all South Africans and people across the world who have been inspired by his remarkable life and example," Ban said.