WASHINGTON (AFP) - The World Bank said Monday it has agreed to provide a 900 million dollar loan to flood-hit Pakistan, saying the economic impact of the disaster on the economy was expected to be huge. The funding will come from the International Development Association, the World Banks arm for low-income countries, a bank statement said. The government of Pakistan has requested around 900 million dollars of financial support from the World Bank, which we have committed to provide, the statement said. Described as the worst humanitarian crisis in the world today, the floods over the last three weeks have affected 20 million people, and destroyed crops, infrastructure, towns and villages, according to the Pakistani government. The economic cost is expected to be huge, the World Bank said Monday. Preliminary information indicated that direct damage from floods was greatest in the housing, roads, irrigation and agriculture sectors, the bank said. It estimated crop loss to be one billion dollars, saying the full impact on soil erosion and agriculture could only be assessed when the water receded by mid-September. Islamabad last week asked the World Bank, the Asian Development Bank (ADB) and the United Nations to carry out assessments in the flood-hit areas in relation to damages, needs and recovery initiatives. The two banks and the UN will collaborate through participation and sharing of information on their respective assessments, and will also regularly coordinate with key donors, the statement said. If there is no fresh wave of flooding, the assessment can be completed by October 15, the World Bank said.