The new head of the United Nations AIDS agency on Tuesday called for global spending on HIV/AIDS programmes to be nearly doubled, but acknowledged that securing $25 billion in the current economic climate would "not be easy." Speaking in Khayelitsha, a sprawling township outside Cape Town, UNAIDS Executive Director Michel Sidibe said: "We cannot let the economic crisis paralyze us. "We cannot let down the 4 million people on treatment and millions more in need today." DPA quoted Sidibe as saying that an amount of $25 billion dollars was required to help countries affected by the HIV pandemic reach their targets on universal access to prevention and treatment by 2010. The current shortfall was around $11.3 billion, he said. Sub-Saharan Africa is the region most heavily affected by HIV worldwide, accounting for two-thirds of all infections and three- quarters of AIDS deaths in 2007. South Africa has the highest number of HIV-positive people in the world, at around 5.7 million. UN member states in 2006 committed to taking extraordinary action to move towards universal access to HIV prevention, treatment, care and support by 2010. Meeting the targets would mean avoiding 1.3 million deaths and around 2.6 million new infections in the next two years, Sibide said.