The international response has been slow to an appeal for emergency funds to help the millions of people hit by last month’s earthquake in Nepal, a UN official said today.

A child injured in Saturday's devastating earthquake in Nepal.

A child injured in the devastating earthquake in Nepal. Image by PA Wire

Jamie McGoldrick, the UN’s chief official in the Himalayan nation, said the agency had received 22 million US dollars so far against an appeal last week for 415 million US dollars to support relief efforts for the first three months.

“This needs to be dramatically ramped up,” he told reporters in the capital, Kathmandu.

The earthquake on April 25 killed more than 7,800 people and injured thousands more. Government figures show that tens of thousands of houses have been demolished and assistance is immediately needed for 400,000 families.

Villagers wait in the rain as an aid relief helicopter lands at their remote mountain village of Gumda, at the epicenter of Saturday's massive earthquake in the Gorkha District of Nepal, Wednesday, April 29, 2015. Image by (AP Photo/Wally Santana).

Villagers wait in the rain as an aid relief helicopter lands at their remote mountain village of Gumda, at the epicenter of Saturday’s massive earthquake in the Gorkha District of Nepal, Wednesday, April 29, 2015. Image by (AP Photo/Wally Santana).

The UN estimates that as many as eight million people have been affected by the 7.8 magnitude earthquake.

Mr McGoldrick said his agency’s main focus now was to reach the many affected people in remote, hard-to-reach areas.

“And we need to do so urgently, so that people have roofs over their heads and their other urgent needs are addressed before the monsoon season starts,” he said.

Houses flattened in an earthquake are seen from an Indian Air Force helicopter in Melamchi, Sindhupalchowk district, Nepal, Friday, May 1, 2015.

Houses flattened in an earthquake are seen from an Indian Air Force helicopter in Melamchi, Sindhupalchowk district, Nepal, Friday, May 1, 2015. Image by (AP Photo/Niranjan Shrestha)

The monsoon rains generally start in the second week of June and often trigger landslides in the mountains and flooding in the southern plains.

But roads are already blocked by landslides triggered by last month’s earthquake and there are fears that rain hitting soil loosened by the earthquake could easily trigger more landslides.

Yesterday, a UN health official said there have been no epidemics in areas hit by the earthquake or in camps where homeless people are sheltered.

Some cases of diarrhoea have been reported, but that is normal for this time of year, said Poonam Singh, the World Health Organiszation’s deputy regional director for Southeast Asia.

(Press Association)