Local staff for international relief agencies are stretched to breaking point and facing tighter restrictions on their ability to deliver a trickle of foreign aid to 1.5 million people facing hunger and disease.

Medicins Sans Frontieres (MSF) said its first cargo plane loaded with medical and logistical supplies landed in the former capital Yangon on Monday. But it was facing "increasing constraints" imposed on its workers in the delta.

US President George W. Bush, speaking after the first US military aid flight to Myanmar on Monday, blamed the military junta for failing to act more quickly to accept international help.

A stream of other aid flights had already landed in Yangon, but only a fraction of the help is reaching where it is needed.

The World Food Programme said it was able to deliver less than 20 percent of the 375 metric tons of food a day it wanted to move into the flooded delta.

France was sending a warship carrying 1,500 metric tons of rice, which was expected near Myanmar later this week. The United States would also have three ships near Myanmar this week, and Britain was sending a navy ship to the region to help humanitarian operations.