In this photograph released by Democratic Voice of Burma on Friday, May 9, 2008, bodies of children killed during Cyclone Nargis lay in water in an unknown location in Myanmar. (AP Photo/str)

Nearly a week after Cyclone Nargis hit the impoverished south Asian country, attention has turned to helping the survivors now at acute risk of malaria, cholera and diarrhea, the World Health Organization warned.

But despite days of increasingly exasperated requests from world leaders, the secretive military regime has only grudgingly begun allowing in aid and rescue workers in dribs and drabs.

On Friday it emerged that Ban had not yet been able to contact General Than Shwe, the head of the Myanmar junta, due to severe damage to the country's telecommunications infrastructure, a UN source said.

Launching the $187-million (120-million-euro) appeal, Ban warned that the lives of those who survived a deadly cyclone could be at risk if the military leaders refuse international aid.

"If early action is not taken and relief measures put in place, the medium-term effect of this tragedy could be truly catastrophic," Ban told a press conference in Atlanta.

"The sheer survival of the affected people is at stake."

German Chancellor Angela Merkel echoed that sentiment and demanded that the UN Security Council unite to push Myanmar to open up to international aid -- despite objections from China.

"I strongly urge the government to assume the responsibility it has to its people and to allow international aid into all the regions hit by the catastrophe," she said.

Canada's parliament denounced the "deplorable response" of the junta, whilst the head of the Association of South East Asian Nations, Surin Pitsuwan, wrote to the junta demanding "quick admission" for aid organizations.

Two World Food Program relief flights are due to arrive in Myanmar Saturday, whilst a US military cargo plane carrying supplies is expected to arrive there Monday.

"One flight is much better than no flights," said US spokesman Gordon Johndroe.

The Red Cross in Geneva said it had managed to get seven visas for its staff, which includes two Australians.

"We expect more people to come through in the coming days," said Michael Annear, regional disaster response coordinator for the International Federation of Red Cross and Red Crescent Societies.

"We are having ongoing discussions with the authorities. So far they've been quite cooperative. We definitely have an open dialogue with the government," he said.

State television in Yangon said Friday after a meeting between its deputy foreign affairs minister Kyaw Thu and the head of the US Embassy, Shari Villarosa that it was prepared to accept US aid -- but without specifying how it would be delivered or distributed.

French Foreign Minister Bernard Kouchner said a French navy ship loaded with 1,500 tonnes of humanitarian aid was en-route for Myanmar and should arrive next Thursday.

"The problem is to know where [the aid] will arrive and how it will be distributed," he said.

The latest official death toll is almost 23,000 dead, with 42,000 missing, but the US has warned that up to 100,000 could have perished. An estimated 1.5 million people have been left homeless by the disaster, many of them now vulnerable to disease and hunger.

A total of $67 million (43 million euros) has already been pledged or given by the international community. That breaks down as $30.7 million already sent and a further 36.1 million pledged by a total of nearly 40 countries, according to the UN's Office for the Coordination of Humanitarian Affairs.

The European Union and the United States have made the largest donations so far, at more than $3 million dollars each, whilst Japan and Britain have pledged the most -- at $10 million each.

Microsoft billionaire Bill Gates said Friday his foundation would donate three million dollars to the relief effort -- to be funneled through independent aid groups such as Care International and World Vision.

China, a neighbour and one of the military regime's few allies, has given $500,000 in cash to the junta, as well as one million dollars' worth of relief supplies including medicine, tents, blankets and water purification kits.