Many relief workers are awaiting visas and most of those who have been allowed into the country remain confined to Rangoon . . . .
According to the Red Cross, aid agencies have been able to reach only around 20% to 30% of cyclone victims and hundreds of thousands of people are at risk of diseases such as dysentery because of lack of clean water.
"If clean water isn't available, it's going to be the biggest killer in the post-disaster environment," Thomas Gurtner told the Associated Press news agency.
Speaking in Geneva, Mr Gurtner predicted "further destitution among an already very hard-hit population", noting that the harvest had already been lost.
The Association of South East Asian Nations (Asean) is due to hold a high-level meeting in the coming days that is expected to lay the framework for a broader aid donors conference.
On Monday, the foreign ministers of all the countries of Southeast Asia -- including the foreign minister of Myanmar -- will sit around a big conference table in Singapore to discuss cyclone relief. Will the actual emergency -- no clean water, no food, the fact that as yet no contact has been made with most victims -- top the agenda, or does this organization just do conferences?