The United Nations and the world's largest backer of programmes against HIV/AIDS said on Sunday they feared wealthy donor nations may cut funding to fight the disease because of global recession, according to Reuters. Speaking at the start of an international gathering of some 20,000 AIDS activists, scientists and HIV patients in Vienna, U.N. Secretary General Ban Ki-moon praised progress made against the human immunodeficiency virus (HIV) that causes AIDS, but said this could be jeopardised if governments trimmed budgets. "Some governments are cutting back on their response to AIDS. This should be a cause for great concern to us all," he told the conference via videolink from New York. Michel Kazatchkine, head of the Global Fund to Fight AIDS, Tuberculosis and Malaria said it needed up to $20 billion in the next three years to sustain progress. "I am hugely afraid. I am very concerned," he told reporters at the Vienna conference. "Because of the (global financial) crisis ... because of the competing priorities." "I hear of many governments cutting official development aid, but I hear other governments saying that despite cuts in other areas, foreign assistance will remain -- and I also hear other governments with good news. It is very up and down." As he spoke, hundreds of protesters marched through the conference centre demanding that rich nations deliver on their promise that all those in needs of AIDS drugs should get them. The Global Fund, set up in 2001, raises donor money every three years and in 2007 secured $10 billion for the 2008-2010 period. The next replenishment meeting is on October 5 in New York and cover the years 2011 to 2013. "I can't believe we will get less, and I can't believe we will be flatlining, but the question is how much more we will get than we got in 2007," Kazatchkine said. CRISIS A report published at the conference by the Joint United Nations Programme on HIV/AIDS (UNAIDS) found that overall support for global AIDS effort from donor nations flattened out last year in the midst of global economic crisis. In 2009, the Group of Eight leading wealthy nations, the European Commission and other donor governments provided $7.6 billion for AIDS relief in developing nations, compared with $7.7 billion disbursed in 2008, it said. The AIDS virus has infected 33.4 million people -- many of them in Africa -- and is transmitted during sex, in blood and on needles and in breast milk. It gradually wears down the immune system and can take years to cause symptoms. It has killed 25 million people since the early 1980s. Kazatchkine said its funding for AIDS, which accounts for around half the fund's spending, was split into three areas -- treatment, prevention and health infrastructure for delivery. A study published earlier on Sunday found that treating HIV patients with cocktails of drugs not only can help them live longer, but can also be a powerful way of limiting the spread of the incurable virus. If the Global Fund manages to get its hoped-for $20 billion dollars for the next three years, Kazatchkine said millions of lives could be saved with HIV treatment and tens of millions of new infections could be prevented. He also said mother-to-child transmission of HIV could be "virtually eliminated", and HIV treatment and testing services could be provided for many more marginalised groups such as sex workers, drug addicts and men who have sex with men. World leaders set this year as a deadline for universal access to treatment for all HIV/AIDS patients who need it, but the head of the International AIDS Society Julio Montaner echoed the tone of protesters, who shouted "broken promises kill". Montaner rebuked politicians for failing to deliver on their promise, saying that only a third of the 15 million people who need potentially life-saving AIDS drugs currently get them. "Today we have treatments that work, we have shown that this can be done ... what we need now is the political will to go the extra mile to deliver on universal access," he said. "We have a serious problem with the political leadership globally and we have to fix it."