The UN chief has called the plight of the Rohingyas in Bangladesh a “humanitarian and human rights nightmare”.
So what has it been like trying to ease the suffering on the ground?
For this latest edition of our UN News podcast, The Lid Is On, we’ll take you inside the biggest and fastest exodus of refugees since the Rwanda genocide of 1994.
More than 600,000 Rohingya - a Muslim minority based in northern Myanmar for generations, who've been denied citizenship – have fled for their lives across the border.
We asked the UN humanitarian affairs office, OCHA, to put us in touch with some of the aid workers who have been dealing with the crisis since the beginning.
Music credit: Ketsa: Where the river run.