Burma's state media say the death toll from cyclone Nargis has reached almost 78,000 and that another 56,000 people are missing.

State television announced the huge increase Friday, two weeks after the disaster. The previous official death toll was 43,000.

Burma's secretive military regime has denied access into the country to most international aid. Four U.S. Navy ships have been waiting in international waters off Burma's coast for several days, ready to deliver fresh water, medicine and other supplies desperately needed by survivors.

The top United Nations official for humanitarian affairs, John Holmes, is traveling to Burma on Sunday to try to convince its leaders to grant access to more aid and to significantly step up efforts to help survivors.

The storm has affected an estimated 2.5 million people, and the United Nations Children's Fund, UNICEF, says up to 40 percent of the storm's victims are children. UNICEF said that as many as one million Burmese children may be at risk of physical and emotional illness following the storm. A spokeswoman Friday said that in addition to a lack of food and clean water, the destruction of homes, schools and sanitation systems remains a threat to surviving children.

The international Red Cross said Friday that fewer than one third of survivors have received aid. It also warned that a lack of clean water could become the biggest killer in Burma's post-disaster environment.

Burma's refusal to increase U.N. and other foreign aid access to cyclone victims has angered the international community.

French and Burmese U.N. envoys had a heated exchange on Friday at the General Assembly in New York. Burma's Kyaw Tint accused France of sending a warship toward the storm-ravaged coast. France's Jean-Maurice Ripert said the ship was carrying humanitarian aid. He said refusal to allow aid to be delivered to people in need could lead to a "crime against humanity."

Some information for this report was provided by AFP, AP and Reuters.