A growing number of people fleeing violence are seeking refuge in Egypt, placing "severe pressure" on under-resourced agencies seeking to support them, the UN said Thursday.

"Ongoing conflicts in Yemen and in Sub-Saharan Africa have forced more people to flee to Egypt", said United Nations refugee agency UNHCR in a statement.

Over the past two years, the number of registered refugees and asylum seekers in Egypt has increased by almost a quarter, it said.

The UN has registered around a quarter of a million refugees and asylum seekers in the country, according to figures published in February.

Most are from war-ravaged Syria, Sudan or Ethiopia.

"Support for refugees in Egypt is under severe pressure due to increased arrivals and inadequate resources," UNHCR warned.

The UN High Commissioner for Refugees, Filippo Grandi, said eight out of 10 refugees in Egypt are living in "desperate humanitarian conditions".

"They cannot meet even their most basic needs. Putting bread on the table is a daily challenge," he said.

But, he said, the agency was operating on a fraction of the budget needed to help them.

"These refugees require timely and adequate humanitarian assistance. Yet, right now we are unable to provide them with the bare essentials or maintain our core refugee protection programmes in this country," he said.

Grandi was speaking days after Egypt hosted a summit of European and Arab leaders, who agreed to work together to manage irregular migration and refugee flows, although without laying out specific measures.

Cairo presents itself as a champion of the fight against irregular migration and a model for integrating refugees on its own territory.