Graca Machel visited Milpark hospital in Johannesburg on Thursday where her husband, former president Nelson Mandela, was being treated.
Machel arrived at 3pm, almost 24 hours after official word was last received on Mandela's condition.
The Nelson Mandela Foundation issued a brief statement just after 4pm on Wednesday reading: “We can confirm that Mr Mandela is at Milpark Hospital undergoing routine tests. He is in no danger and is in good spirits.”
There had been no further communication from the foundation by 3.30pm on Thursday.
The Star reported Mandela was airlifted from Cape Town to Milpark hospital by military aircraft after he developed a persistent cough. The hospital was not planning to comment on the 92-year-old statesman's condition.
The Freedom Front Plus called for more information to prevent uncertainty and rumours.
“Because Mr Mandela is internationally a well-known figure, we would like to request that as much information as is possible is continually made known about the state of his health,” said MP Pieter Mulder in a statement.
“It is the only way in which uncertainties and rumours about Mr Mandela can be prevented.”
The party wished him a speedy recovery.
Democratic Alliance leader Helen Zille also wished Mandela well.
“On behalf of the Democratic Alliance, I wish Madiba a speedy and healthy discharge from hospital. Our thoughts are with him and his loved ones. We must respond to the current situation with the dignity and calm that he would expect,” she said in a statement.
Earlier, President Jacob Zuma wished Mandela well and said he was “comfortable” and being “well looked after”.
“President Mandela is comfortable and is well looked after by a good team of medical specialists,” the presidency said in a statement.
“We urge the media to afford him the dignity and respect that he is entitled to as the country's founding democratic president, as a national hero and also as a citizen of the republic.
“The doctors also need to be allowed to do their work without undue pressure.”
Zuma was being kept abreast of developments while attending the World Economic Forum annual meeting in Davos, Switzerland.
Minister of Defence and Military Veterans Lindiwe Sisulu, whose department was responsible for the health care of current and former presidents, was keeping Zuma up to date.
Family members and politicians visited the hospital on Thursday.
Winnie Madikizela-Mandela wiped her face and blew her nose as she left the hospital around 1.30pm. She was accompanied by Mandela's eldest grandson, chief Mandla Mandela and other family members.
Anti-apartheid activist Albertina Sisulu waved and smiled as she was driven out of the hospital grounds.
Justice Minister Jeff Radebe, Mandela's personal assistant Zelda la Grange, and the daughter of Mandela's wife Graca Machel, and senior military officials were at the hospital.
Meanwhile, Archbishop Emeritus Desmond Tutu asked journalists in Bloemfontein on Thursday what more the country wanted from former president Nelson Mandela.
“What more do we want from him? We want him to remain forever, but you know... anything can happen,” Tutu said at the opening of the International Institute for Studies in Race, Reconciliation and Justice at the University of Free State.
Tutu confirmed he saw Mandela last week, and remarked that for a 92-year-old he was “amazing”.
Mandela had done a fantastic job and the country should thank God for him, said Tutu.
A large contingent of local and international media were barred access to the Milpark hospital premises on Thursday.
Three journalists from a Chinese news agency snuck past security into the hospital before having their cameras confiscated by police. The cameras were later returned.
Meanwhile, police cordoned off the entrance to Mandela's house in Houghton, north of Johannesburg.
“The presidential protection unit has cordoned off a small section in front of his house,” Colonel Vish Naidoo told Sapa.
He said this was being done as a precaution in case people wanted to visit Mandela's home to pay homage.
The Star newspaper reported on Thursday that Mandela was seen by Professor Michael Plit, a specialist pulmonologist (who deals with diseases of the respiratory system).
“He has been admitted for investigation,” Plit was quoted as saying.
He would not say what Mandela's condition was or if he had examined him, except to say he had seen him on Wednesday.
On the National Asthma Education Programme website, Plit describes his medical interests as obstructive lung diseases, such as asthma and chronic obstructive pulmonary disease.
ANC spokesman Jackson Mthembu issued a statement calling for the media to stop speculating about Mandela's health and allow the family privacy.
He said South Africans would be informed of any change, including if Mandela were to be discharged from hospital.
The ANC Youth League sent its best wishes.
“Nelson Mandela remains our greatest inspiration in everything we do and we confident (sic) that he will stay strong,” a league statement read. -
Sapa