Hit by an unprecedented crisis, Pakistan's top leadership today appealed to the United Nations to send a strong message to the world community and foreign corporate leaders to help the country in providing relief to millions of people affected by the floods. President Asif Ali Zardari and Prime Minister Yousuf Raza Gilani raised the issue with visiting UN Secretary-General Ban Ki-moon, who arrived in Islamabad today to boost relief efforts for the 20 million people affected by the deluge. Zardari called for greater international support and aid to cope with the gigantic task of relief and rehabilitation of the flood victims and the reconstruction of damaged property and infrastructure. Over 1,700 people have been killed by the floods, which also washed away roads, bridges and communications infrastructure in a wide area ranging from Khyber-Pakhtunkhwa province in the northwest to southern Sindh province.