The United Nations launched on Tuesday an appeal for $333 million in emergency funding for 1.6 million people it said were affected after deadly Cyclone Mocha tore through Myanmar.
Mocha brought lashing rain and winds of 195 kilometres per hour (120 miles per hour) to Myanmar and neighbouring Bangladesh on 14 May, collapsing buildings and turning streets into rivers.
Myanmar's junta has given a death toll of 148 people, mostly from the persecuted Rohingya minority in western Rakhine state.
The UN's humanitarian affairs office said it was seeking $333 million to help provide shelter, medical facilities, food and clean water ahead of the rainy season.
"We are now in a race against time to provide people with safe shelter in all affected communities and prevent the spread of water-borne disease," Resident and Humanitarian Coordinator Ramanathan Balakrishnan said in a statement.
More than $200 million would come from the overall humanitarian aid plan for this year in Myanmar, the statement added, with $122m sought to support new relief efforts for those affected by the cyclone.
Balakrishnan later told reporters the United Nations was hoping to receive approval soon to distribute relief to communities in Rakhine.
The state is home to hundreds of thousands of Rohingya, many of whom live in displacement camps following decades of ethnic conflict.
A military crackdown in Myanmar in 2017 sent hundreds of thousands of Rohingya fleeing into neighbouring Bangladesh, with harrowing stories emerging of murder, rape and arson.
A junta spokesman did not respond to AFP questions about whether UN agencies would be granted access to displacement camps in Rakhine that house Rohingya.
Junta chief Min Aung Hlaing, who was head of the army during the 2017 crackdown, has dismissed the term Rohingya as "imaginary".
In Bangladesh, officials told AFP that no one had died in the cyclone, which passed close to sprawling refugee camps that now house almost one million Rohingya.
The appeal comes after the UN's food agency said Monday that lack of funding has forced it to cut food aid for around one million Rohingya refugees living in camps in Bangladesh for the second time in three months.