The United Nations said on Monday it is seeking $6-billion for Sudan this year from international donors to help ease suffering in what it called one of the most devastating crises of our times, characterised by mass displacement and growing famine.

The UN appeal represents a rise of more than 40% from last year's for Sudan at a time when aid budgets around the world are under increasing strain, partly due to a pause in funding announced by US President Donald Trump last month that has affected life-saving programs across the globe.

But the UN says the funds are necessary because the impact of the 22-month war between Sudan's army and the paramilitary Rapid Support Forces (RSF) - that has already displaced a fifth of its population and stoked severe hunger among around half its population - looks set to worsen.

"Sudan is a humanitarian emergency of shocking proportions," said UN Emergency Relief Coordinator Tom Fletcher ahead of the launch. "Famine is taking hold. An epidemic of sexual violence rages. Children are being killed and injured. The suffering is appalling."

Famine conditions have been reported in at least five locations in Sudan, including displacement camps in Darfur, the UN statement said, adding that this was set to worsen with continued fighting and the collapse of basic services.

One of the famine-stricken camps was attacked by the RSF last week as the paramilitary group tries to tighten its grip on its Darfur stronghold.

While some aid agencies say they have received waivers from Washington to provide aid in Sudan, uncertainty remains on the extent of coverage for providing famine relief.

The UN plan aims to reach nearly 21-million people within the country, making it the most ambitious humanitarian response so far for 2025, and requires $4.2-billion - the rest being for those displaced by the conflict.