As the conflict in Sudan nears its one-year mark, the UN Refugee Agency is warning that over 25 million people are facing a humanitarian crisis with no end in sight.

Ahead of the anniversary of the conflict on April 15, UNHCR said that Sudan and its neighbours are experiencing one of the largest and most challenging humanitarian and displacement crises in the world.

Thousands of refugees have continued to cross borders daily as they flee the war, with most arriving in South Sudan. The number of displaced people has "now surpassed 8.5 million people, with 1.8 million of them crossing borders," said Olga Sarrado, UNHCR spokesperson.

635,000 of the displaced have fled to South Sudan, representing over 5 percent of South Sudan's population. The refugees are in desperate need of food, water, shelter, and medical care, with many families having been separated and in distress.