Nepalese Prime Minister Sushil Koirala says that Nepal is "on a war footing" as it tries to help survivors following Saturday's earthquake.
Sushil Koirala said the government was doing all it could but was overwhelmed.
The UN has estimated that eight million people have been affected - more than a quarter of the population. Foreign aid is arriving but being hampered by congestion at Kathmandu's sole airport.
The death toll from the 7.8-magnitude quake is now 4,356, but Koirala said it could reach 10,000.
Koirala said that the government is doing all it can for rescue and relief on a war footing" in a "difficult hour" for Nepal, and he has also admitted that lack of equipment and expert personnel meant the "appeals for rescues coming in from everywhere" in many cases, could not be met.
Water, food and electricity are in short supply and there are fears of outbreaks of disease.