CAPE TOWN - Graca Machel, wife of former South African President Nelson Mandela, on Monday thanked South Africans and the whole world for their well wishes for Mandela who has been hospitalized for the 10th day.

"So much love and generosity from South Africans, Africans across the continent, and thousands more from across the world, have come our way to lighten the burden of anxiety; bringing us love, comfort and hope," Graca said in a message posted on the website of Nelson Mandela Centre of Memory.

Mandela, 94, was rushed to a Pretoria hospital from his Johannesburg home on June 8 for a recurring lung problem.

According to the latest update by President Jacob Zuma on Sunday, Mandela "continues to get better".

"Over the last two days, although he remains serious, his doctors have stated that his improvement has been sustained," Zuma said at a rally to commemorate the country's National Youth Day in Newcastle, KwaZulu-Natal Province.

Since Mandela was hospitalized, well wishers have come to his Johannesburg home or the hospital where he was receiving treatment to show their support for the anti-apartheid icon.

"The messages have come by letter, by SMS, by phone, by twitter, by Facebook, by email, cards, flowers and the human voice, in particular the voices of children in schools or singing outside our home. We have felt the closeness of the world and the deepest meaning of strength and peace," Graca said.

"Our gratitude is difficult to express. But the love and peace we feel give yet more life to the simple Thank you!" she said.

Graca quoted Mandela's words as saying: "What counts in life is not the mere fact that we have lived. It is what difference we have made in the lives of others."

"I have thought of his words on each occasion the world stood with him, making a difference to him, in his healing," Graca said.

Mandela, who served as South Africa's first black president from 1994 to 1999, has long suffered a lung infection which was the result of tuberculoisis developed when he served a 27-year term in prison under the apartheid rule.

He has been in and out of hospital several times since last December, raising concern about his frail health.