The country is still struggling to cope with the fallout from Cyclone Nargis 11 days ago, which is believed to have killed more than 100,000 people.

More than one million others have also been left in need of international aid.

The UN now says another massive storm is currently forming near Burma, but it remains unclear if it will become a cyclone or where it might make landfall.

"The potential for the development of a significant tropical cyclone within the next 24 hours is upgraded to good with the only limitation being temporary land interaction," said a report by the Joint Typhoon Warning Centre, a website used by US government agencies.

The JTWC website said the depression was currently 30 nautical miles west-southwest of Rangoon.

Amanda Pitt, spokeswoman for the United Nations humanitarian relief program, told reporters another cyclone is likely, saying: "This is terrible. The government has a responsibility to assist their people in the event of a natural disaster.

"We are here to do what we can and facilitate their (Burma's) efforts and scale up their response.

"It is clearly inadequate and we do not want to see a second wave of death as a result of that not being scaled up."

International agencies have called on the country's secretive military junta to allow immediate access to those stranded without food, clean water and medicines.

Cholera, typhoid and malaria could take hold within days as lack of food and shelter weakened the resistance of survivors.

Over 100,000 people are believed to have died in the 130mph winds and storm surges that hit the country last weekend.

Oxfam has warned that 1.5 million people could die needlessly in Burma as the first outbreaks of disease were reported in the wake of Cyclone Nargis, and many of the worst-hit areas went an eighth day without aid.