The upcoming monsoon season will exacerbate the crisis in the aftermath of two devastating earthquakes that hit Nepal in the last three weeks, UN Secretary-General Ban Ki-moon warned Friday.

"With the monsoon season starting in June, there is an urgent need to make sure that nearly half a million people have emergency shelter before the rains start in earnest", Ban told a UN General Assembly session on the humanitarian situation in the landlocked South Asian country.

He said the season, which brings large amounts of rainfall to the region, would worsen the already dire humanitarian conditions and increase the danger of cholera and other water-borne diseases.

"I cannot stress enough the importance of getting aid, including clean water and sanitation supplies, to everyone in need within the next few weeks", he added.

A 7.8-magnitude earthquake April 25 killed more than 8,100 people and injured almost 18,000, according to Nepali authorities. 

Two weeks later, a second major quake with a magnitude of 7.3 jostled the country, killing at least 50 people.

The UN chief said the quakes wiped out years of development gains.

"Tens of thousands of people who had been brought out of poverty are at risk of falling back", he added.

On April 28, the UN appealed for $415 million to provide emergency shelter, water and food to the 8 million people it said had been affected.

But just $60 million of the request has been raised to date, according to the New York-based body.

"Needless to say, the 14 percent funding is far from sufficient. Let us resolve to do more and better", Ban said.

Anadolu Agency