First China, now Burma declares three days of mourning for 78,000 cyclone dead

The military government has allowed relief flights to deliver supplies to Yangon, the largest city, but had balked at aerial access to the southwestern Irrawaddy delta, where an estimated 2.4 million people were left destitute.

"We have received government permission to operate nine WFP helicopters which will allow us to reach areas that have so far been largely inaccessible," Ban told reporters before departing for a visit to Myanmar.

Desperate: Displaced families prepare to leave in search for shelters in the cyclone-hit Shwepoughkan township

The top UN humanitarian envoy, John Holmes, said in Myanmar on Tuesday he had discussed the use of helicopters with government officials, who "took note" of his suggestion.

The junta's delays in allowing access to international aid workers has drawn criticism and warnings that many more people could die in the aftermath of the cyclone that roared across parts of the Southeast Asian country at the start of May.

Ban said he welcomed the government's "recent flexibility" but added that aid workers had so far been able to reach only around 25 percent of those in need.

He said he hoped Myanmar's reclusive leader Than Shwe would be among senior government officials he meets during his visit. Ban was due to arrive in the Thai capital Bangkok on Wednesday and go to Myanmar on Thursday.

Horror: The body of a small child killed by Cyclone Nargis floats just off the shore of the Pyapon River, near Piyapon

Ban said that a May 25 donors' pledging conference in Yangon would be crucial for the longer term rebuilding of the country, where he said the government had estimated the cost of the disaster at some £5 billion in economic losses.

Meanwhile, the junta has declared three days of official mourning, two weeks after a cyclone killed 78,000 people in the country.

Yesterday's decision came just hours after China announced three days of mourning for its own earthquake victims.

The official death toll is 78,000 with 56,000 missing, but unofficial estimates suggest 217,000 are dead or missing.

The charity Save the Children warned yesterday that thousands of children could die of starvation in the next three weeks.

Gordon Brown has accused Burma's military leaders of turning the cyclone that hit on May 2 into a "man-made catastrophe".