World leaders hold a landmark health summit on Monday that is expected to launch an acrimonious debate on the cost and responsibility for diseases killing tens of millions each year. More than 36 million people a year die from cancer, heart disease, diabetes and other non-communicable diseases (NCDs) which are the topic of the summit starting the UN General Assembly week in New York.About 35 heads of state and government and 50 health and foreign ministers are to attend the two day meeting which must take the first steps to pushing governments into greater preventive measures.The spread of non-communicable diseases is particularly alarming in Africa, the Middle East and Asia with poorer countries suffering most, experts say. About 80 percent of the deaths are in developing countries.The summit\'s draft final statement takes tentative steps toward laying the blame for the deaths. UN states \"recognize that the most prominent NCDs are linked to common risk factors, namely tobacco use, harmful use of alcohol, and unhealthy diet, and lack of physical activity.\" The final statement also says more help must given to poor countries. It calls non-communicable diseases \"one of the major challenges for development in the 21st century. \"Poor populations and those living in vulnerable situations, in particular in developing countries bear a disporportionate burden.\" Anne Keeling, president of the NCD Alliance, which groups about 2,000 health organisations around the world. said the diseases are now at \"epidemic level\" and are a challenge to be confronted by all countries.Keeling, who is also chief executive of the International Diabetes Federation, said there are currently about 344 million diabetes sufferers around the world and the number will soon pass 500 million within a generation. The summit statement says prevention must be the cornerstone of international efforts. Many experts are urging leaders to take a tougher stand however. Even the UN\'s special rapporteur on the right to food has called for taxes on unhealthy food and regulating harmful marketing practices. \"Voluntary guidelines are not enough. World leaders must not bow to industry pressure,\" the expert, Olivier De Schutter, said in a statement ahead of the two day summit. \"It is crucial for world leaders to counter food industry efforts to sell unbalanced processed products and ready-to-serve meals too rich in transfats and saturated fats, salt and sugars,\" he said.Aid for the poor countries battling the new wave of non-communicable diseases will also be an issue at the summit.It currently makes up less than three percent of official development aid, a lot less than sums given to tackle transmissible diseases like malaria, said Ala Alwan, deputy director general of the World Health Organization. The summit declaration says there should be \"policies and actions aimed at promoting healthy diets and increasing physical activity in the entire population.\" It proposes initiatives to reduce salt, sugar and saturated fats in our diets. Many experts are hungry for even more cutbacks on the dinner plate.