Multiple states and regions affected in a country already plunged into crisis by the February 2021 coup.
At least 236 people have been confirmed dead after Typhoon Yagi caused severe flooding in several regions of Myanmar.
Some 77 people remain missing, the state-run Global New Light of Myanmar reported on Tuesday, citing official figures.
The United Nations Office for the Coordination of Humanitarian Affairs (OCHA) indicated the toll could be even higher.
“Multiple sources indicate that hundreds of people have died, with many more missing,” it said in an update on Monday, saying an estimated 631,000 people might have been affected by the floods.
Typhoon Yagi, one of the strongest storms to hit the region this year, swept across southern China, Vietnam, Laos and Myanmar last week bringing torrential rain. Hundreds have already been confirmed dead in northern Vietnam.
In Myanmar, flooding has affected at least nine regions and states including the capital Naypyidaw, as well as the central Mandalay region as well as Kayah, Kayin and Shan States.
The flooding comes at a time when thousands have been forced from their homes by escalating conflict between the military and forces opposed to their February 2021 coup. At least three million people in Myanmar are estimated to have been displaced by conflict, according to the UN.
The generals have previously rejected or frustrated international offers of help, including after Cyclone Mocha struck western Rakhine State in May 2023, but over the weekend issued a rare call for outside assistance.
The OCHA said there was an urgent need for food, drinking water, medicine, clothes and shelter, but that damaged roads and bridges as well as unstable telecommunication and internet services were hampering relief efforts.
The Special Advisory Council for Myanmar (SAC-M), an independent group of international human rights experts, said it was crucial that neighbouring countries engage with resistance authorities and civil society to get assistance to those most in need.
“The Myanmar military junta is not the legitimate or de facto government of Myanmar, nor does it have the will or capacity to ensure aid is delivered to the majority of those in dire need,” the SAC-M said in a statement. “The military created Myanmar’s pre-existing humanitarian crisis and will seek to use engagement with international actors on humanitarian grounds to advance its own military and political agenda at the expense of the Myanmar people.”
OCHA noted that Myanmar relief efforts also faced severe funding issues with only 25 percent of this year’s Myanmar response currently funded.