NEW DELHI (AFP) - UN Secretary General Ban Ki-moon warned Thursday that poor nations could be hurt most by the global financial crisis and called for swift action to tackle the roots of the turmoil. Ban issued the warning in a speech after arriving in New Delhi on his first official trip to South Asia during which he will also travel to Nepal and Bangladesh. "The least developed countries, the poorest of the world's poor " children, older persons and others " stand to suffer most," he said in a lecture at the Rajiv Gandhi Memorial Foundation set up to honour the slain former Indian prime minister. "I am very worried development assistance will suffer and that investors might pull back from emerging markets," Ban said. "People who have striven so hard to rise out of poverty could fall back into destitution." "We cannot know what twists and turns the crisis will take next. But we do know that it requires an urgent, coherent and concerted collective response," he said. There was a "pressing need to address the systemic weaknesses at the root of the crisis," the UN Secretary General said  He also called for "institutional mechanisms that will help minimize the risk of both market and regulatory failures." There is also an urgent need to revive global trade negotiations, he said. "We should rededicate ourselves to reaching an ambitious, pro-poor outcome to the Doha Development Round. We need leadership from all sides, including India," he said. The Doha Round, launched in 2001 in the Qatari capital, has repeatedly missed deadlines set for its conclusion. The latest talks fell apart earlier this year due to a deadlock between India and the US over import tariffs and subsidy levels. Ban also called for India to help tackle global warming. "The world is watching India. We all know the challenges India is facing. But confronting the shared challenge of stabilizing our climate will require give-and-take from every single country." "We look for Indian leadership. It is time for India to move towards a low-carbon future, consistent with its development aspirations," he said. The world's biggest emitter for decades has been the United States, accounting for more than 20 percent of the world's production of carbon dioxide emissions. But emissions have also rapidly grown in the developing world " China is now in second place at 16 percent and India is among the top five emitters at six percent. Developing countries say they cannot yet make commitments to cut their emissions because it will hamper economic growth. Ban will hold talks with Prime Minister Manmohan Singh during the two-day visit. New Delhi, which wants a seat on the Security Council, was expected to raise the issue of UN reforms, including expansion of the 15-member Council, during Ban's visit, officials said. India says its 1.1-billion-plus population, its status as the world's biggest democracy, growing economy and big contribution to UN peace-keeping efforts entitles it to a permanent place at the table. Ban will leave Friday for Nepal where he will meet the Himalayan nation's newly installed Maoist-rebel-turned premier Pushpa Kamal Dahal. On Saturday, Ban will hold talks with leaders of Bangladesh's interim army-backed government. Polls to transfer power to a civilian government after almost two years of emergency rule are due December 18.