Obama to laud \'improving\' Mandela

US President  Barack Obama will express \"profound gratitude\" for Nelson Mandela Saturday, as his hero\'s battle for life adds an emotional edge to his first visit to South Africa as president. Obama said he did not need a photo-op with Mandela following speculation he could visit the anti-apartheid icon and his fellow Nobel peace laureate in the Pretoria hospital where he has been for more than three weeks. Fears for Mandela health, weighing heavily on Obama\'s three-nation Africa tour, eased slightly Friday, as the 94-year-old\'s ex-wife Winnie said there had been a \"great improvement\" though he was still said to be in a critical condition. Obama, who met Mandela once in Washington in 2005, said his primary concern was for the comfort of the ex-South African president and the well-being of his family. \"The last thing I want to do is to be in any way obtrusive,\" Obama said as he flew from Senegal to South Africa, the second leg of a three-nation tour his administration sees a chance to make up for lost time on the continent. \"I think that the message we\'ll want to deliver is not directly to him but to his family, is simply profound gratitude for his leadership all these years,\" Obama said. Mandela, who turns 95 next month, has been in intensive care for three weeks for a recurrent lung disease dating from his years in apartheid-era prisons. But after taking a turn for the worse last weekend, he has since shown tentative signs of recovery. Supporters have been gathering outside the hospital to offer prayers for the man who negotiated an end to decades of racist white minority rule and went on to become South Africa\'s first black president. \"I came to pray for our father Nelson Mandela. We are wishing for our father to be fine,\" said Thabo Mahlangu, aged 12, part of a group from a home for abandoned children who travelled to Pretoria. A wall of handwritten prayers for Mandela\'s recovery has become the focal point for South Africans paying tribute to the father of their nation, with singing and dancing by day and candlelight vigils at night. One message read: \"If you can fight prison, you can beat this\". Another said: \"You are such an incredible inspiration to millions\". A visit by Obama to Mandela\'s former jail cell on Robben Island, off Cape Town, on Sunday in particular is expected to be laden with symbolism. Before then, Obama will try to make sure that the main message of his tour, that the United States sees Africa as poised for explosive growth after years as an aid recipient, is not eclipsed. He will hold talks and a press conference in Pretoria on Saturday with President Jacob Zuma before travelling to Soweto to hold a town hall style conversation with young leaders from all over the African continent. Back in Pretoria Saturday evening, Zuma will throw an official dinner for the US leader. After touring Robben Island Sunday, Obama will visit former Archbishop Desmond Tutu\'s youth foundation HIV centre before delivering the central speech of his African tour at the University of Cape Town. Obama leaves South Africa Monday, for the final stop on his tour, Tanzania. The US leader will not be greeted warmly by all South Africans. \"NObama\" demonstrations were held in Pretoria by a coalition of leftist, pro-Palestinian and anti-drone groups. The group was protesting against what it described as the \"arrogant, selfish and oppressive foreign policies\" of the United States. Mandela has been hospitalised four times since December, mostly for a stubborn lung infection. The man once branded a terrorist by the United States and Britain walked free from prison near Cape Town in 1990. He won South Africa\'s first fully democratic elections in 1994, forging a path of racial reconciliation during his single term as president, before taking up a new role as a roving elder statesman and leading AIDS campaigner. As he languishes in hospital, his relatives are fighting a legal battle, reportedly over where members of the family should be buried. On Friday, sixteen members of the Mandela family brought an urgent application to a regional court, reportedly to force Mandela\'s grandson Mandla to return remains of family members to a plot in the ancestral village where Mandela has said he wants to be buried. Mandla, a local chief in nearby Mvezo, had exhumed the remains of three of Mandela\'s children in Qunu in 2011 and brought them to his village, allegedly without the consent of the rest of the family.