Only a fraction of the emergency funds the United Nations has requested for victims of Nepal's earthquake have come in, UN officials have said, as crises around the world put unprecedented demands on international donors.

Of the $415 million requested by the UN and its partners last week, just $22.4 million has been provided - about five percent.

"It's a poor response," Orla Fagan, spokeswoman for the United Nations Office for the Coordination of Humanitarian Affairs, told the Reuters news agency on Thursday.

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Fagan attributed the shortage to "donor fatigue", citing more than a dozen other long-running international crises, such as the conflicts in Syria and Iraq, which are also making demands on donor nations.

The 7.8 magnitude earthquake that struck northwest of Nepal's capital Kathmandu on April 25 has killed at least 7,759 people, injured more than 16,000, and destroyed more than 300,000 homes.

Nepal's post-disaster response has been heavily criticised in the 10 days following the earthquake. Many people in rural areas have still not received any government aid. The UN and Western governments have blamed the country's bureaucracy for taxing and stalling the flow of supplies at border crossings.

The government, however, has denied those accusations.

"Nepal is a very small country, we have limited resources," Brigadier General Jagadish Chandra Pokharel told Al Jazeera this week. "The terrain is inaccessible even under ideal circumstances. We have no conflict and good relations, so 90 percent of military personnel are focused on relief efforts."