Singapore, June 25:

Asian countries need help to build cities that can cope with the region’s “unprecedented” urban expansion of more than 100,000 people a day over the next two decades, the Asian Development Bank said today.

Half of Asia’s population will be living in cities by 2020, as some 1.1 billion people move to the urban environments over the next 20 years, said ADB President Haruhiko Kuroda at a conference on sustainable cities in Singapore.

“Asia’s rapid urbanisation is unpr-ecedented,” Kuroda said. “Providing jobs and services while improving livelihood and quality of life for so many city dwellers is an urban management task of a magnitude never before attempted by humanity.”

“For most major cities in Asia, growth rates are too rapid for their own infrastructure to keep up with and the benefits of new investments and infrastructure have not been distributed equally,” he said.

Kuroda said that there was a $30 billion shortfall every year in the maintenance of urban infrastructure in the region, leading to greater deterioration of the existing infrastructure — already more than half a billion Asians currently live in slums and air pollution is affecting the health of millions.

By 2015, more than half of global greenhouse gas emissions will come from cities in Asia, Kuroda added. “Clearly, Asia’s cities need assistance in coping with the physical impact of past and current urban growth,” he said.

“They need increased investments in sustainable infrastructure, which will only come through more appropriate and relevant financing options.” Providing access to safe drinking water and proper sanitation is another challenge that many Asian countries face, Kuroda said.

He warned that the health, social and economic costs of the region’s deteriorating water quality are likely to be high already and will only rise further if improvements are not made. He added that there is greater urgency now for countries to tackle problems with water supply management in both urban and rural settings.

“Given the recent trend of soaring food prices, the urgency of increasing investment in rural water services to improve farm production and productivity has heightened significantly,” he said.

The Manila-based development lending institution last month announced $500 million in emergency aid for poor countries struggling with soaring food prices. It will also double its lending for the agricultural sector in 2009 to $2 billion.