UNITED NATIONS, April 26 -- UN officials called on Sunday for joint effort in the search and rescue operations in the wake of a powerful earthquake that shook Nepal on Saturday and killed thousands.

"The actions of the government of Nepal and local communities themselves have already saved many lives," said Valerie Amos, the UN under-secretary-general for humanitarian affairs, in a statement issued here. Amos is also the UN emergency relief coordinator.

"Teams from India, Pakistan, China and Israelhave started work, and more are on their way from the U.S., the UK, Singapore, the United Arab Emirates, the European Unionand elsewhere," she said.

The latest number of the killed is 3,218, Nepalese authorities said Monday morning.

A staggering 7.9-magnitude quake, the worst to hit the nation in over 80 years, shook central, western, mid-western and far-western parts of Nepal at midday on Saturday, leaving tens and hundreds of people injured and causing damage to properties worth billions of U.S. dollars.

In the capital Kathmandu, thousands of people had spent the night on pavements, in parks and open fields in chilly temperatures, too afraid to return to their ramshackle homes.

Most of historic buildings in the worst-hit Kathmandu Valley were destroyed in the catastrophe while a 6.7-magnitude aftershock jolted Nepal on Sunday.

Homes and buildings have collapsed and entire areas have been flattened. People need food, water, emergency shelter and healthcare, she noted. "Many families have slept in the open in makeshift tents for two nights."

"Our thoughts are with the people of Nepal as they deal with the loss of life and devastation caused by Saturday's earthquake and aftershocks," Amos said.

The United Nations agencies in Nepal, with their humanitarian partners, are supporting the Nepalese government and other partners, she said.

A team from the World Food Programme is on the ground providing food items and trucks for distribution, the UN Children's Fund (UNICEF) is sending tents and healthcare supplies, and the World Health Organization has distributed medical supplies to cover the immediate needs of 40,000 people, Amos said.

A United Nations Disaster Assessment and Coordination team is on the ground helping to coordinate response efforts.

Also on Sunday, the president of the UN Economic and Social Council (ECOSOC), Martin Sajdik, said in a separate statement issued here that "I am deeply saddened by the loss of life and the destruction inflicted upon the people of Nepal by this massive earthquake."

"At this time of tragedy, our hearts and condolences go immediately to all who have lost family members and to those who were injured in this disaster," the president said.

The full scope of the disaster is not yet known but it is known that its cost goes well beyond the damage to property and has immense economic and social impact on Nepali society, he said, adding that as a "least developed country," Nepal can ill afford these setbacks on its path to sustainable development.

"As we prepare for the September Summit on the post-2015 development agenda, I call again on world leaders to take the necessary steps towards making disaster risk reduction a critical component of the post-2015 development agenda," he said. "We also need to ensure that our mitigation efforts are more effective and we minimize the impact of such disasters."

At this time, "our primary duties" are three fold: first, to assess the damage, second, to ensure that a global humanitarian assistance is delivered urgently to Nepal, and third, the development gains are not lost, he said.

"I call on Nepal's partners, United Nations humanitarian and development organizations, the international community as a whole, including non-governmental organizations and the private sector to quickly provide assistance to the country," he said. "And, also focus on its long-term recovery."

The Economic and Social Council reaffirms its solidarity with the people of Nepal and pays tribute to their immense resilience and courage,the president said. "Through coordination and cooperation, we can all mobilize our efforts to help Nepal in this time of great need and for its path to sustainable development."

On Saturday, UN Secretary-General Ban Ki-moonon Saturday sent his deepest condolences to the government of Nepal and to everyone affected after the quake hit the Kathmandu Valley in Nepal, according to Ban's statement.

"Our thoughts are with the people of Nepal and neighbouring countries today in the aftermath of the earthquake that has struck the Kathmandu Valley," Ban said.