US First Lady Laura Bush started a four-nation Africa tour that is expected to focus on how the United States can help fight AIDS on a continent where many countries struggle to even provide basic health care. Laura Bush, accompanied by her daughter Jenna, is scheduled to visit areas that have benefited from US AIDS funding this week - the west African nations of Senegal and Mali, along with Mozambique and Zambia in southern Africa. The US first lady and her daughter were greeted on the tarmac in Senegal's seaside capital late Monday by a group of about 30 dignitaries, including Senegal's first lady, Viviane Wade, and her daughter. The two first ladies shook hands and posed for photographs, but neither spoke to reporters. Last month, President George W. Bush called on Congress to authorize an additional $30 billion (â‚¬22.3 billion) to fight AIDS in Africa, a figure that would double the US commitment to the continent. The current program, which provided $15 billion (â‚¬11 billion) over five years, expires in September 2008.