A senior U.N. official who just returned from Nepal says the top priority now is finding temporary housing for hundreds of thousands of people before monsoon rains begin.

The rainy season in South Asia runs from June through September and Magdy Martinez-Soliman, assistant administrator of the U.N. Development Program, said "it's a daunting task" to protect half a million families from the monsoons and the coming winter.

Martinez-Soliman said Tuesday a major assessment of damage and reconstruction needs is currently underway by experts from the World Bank, UNDP, the European Union and many other organizations.

While most photos have focused on devastated urban areas, Martinez-Soliman said "the disaster is predominantly rural."

He said the main losses are 500,000-600,000 homes that are destroyed or unsafe as a result of damage.