The death toll from the cyclone that battered Myanmar last weekend rose above 22,000 Tuesday as the international community prepared to rush in aid, state radio reported. A news broadcast on government-run radio said that 22,464 people have now been confirmed dead from Cyclone Nargis, which tore through the country's rice bowl and biggest city of Yangon early Saturday. The broadcast added that thousands more are missing. Relief efforts for the stricken area, mostly in the low-lying Irrawaddy River delta, have been difficult, in large part because of the destruction of roads and communications outlets by the storm. In the cyclone's aftermath, state radio reported that the government was delaying a constitutional referendum in areas hit hardest. Saturday's vote on a military-backed draft constitution would be delayed until May 24 in 40 of 45 townships in the Yangon area and seven in the Irrawaddy delta, which took the brunt of the weekend storm, the radio said. It indicated that the balloting would proceed in other areas as scheduled. The UN World Food Program, which was preparing to fly in food supplies, offered a grim assessment of the destruction: up to a million people possibly homeless, some villages almost totally destroyed and vast rice-growing areas wiped out. "We hope to fly in more assistance within the next 48 hours," WFP spokesman Paul Risley said in Bangkok. "The challenge will be getting to the affected areas with road blockages everywhere." Based on a satellite map made available by the United Nations, the storm's damage was concentrated over about a 30,000-square-kilometer area along the Andaman Sea and Gulf of Martaban coastlines - less than 5 percent of the country. But the affected region is home to nearly a quarter of Myanmar's 57 million people. Images from state television showed large trees and electricity poles sprawled across roads as well as roofless houses ringed by water in the delta, regarded as Myanmar's rice bowl. Aid agencies reported their assessment teams had reached some areas of the largely isolated region but said getting in supplies and large numbers of aid workers would be difficult. Richard Horsey, Bangkok-based spokesman for the UN Office for the Coordination of Humanitarian Aid, said the airport closest to the delta region was located in Yangon. "For those places accessible by land, there will be cars and trucks from those areas to meet at the halfway point with vehicles from Yangon," he said. "For remote areas, assessment teams and assistance teams will need to go by helicopters and boats." The delta is riddled with waterways but Horsey said they are not easily accessible, even during normal times. "More or less all the land lines are down and it's extremely difficult to get information from cyclone-affected areas. But from the reports we are getting, entire villages have been flattened and the final death toll may be huge," said Mac Pieczowski, who heads the International Organization for Migration office in Yangon, in a statement. The country's ruling military junta, which has spurned the international community for decades, urgently appealed for foreign aid at a meeting Monday among Nyan Win and diplomats in Yangon. "Instead of waiting for figures on casualties and damage, it will be practical to send humanitarian aid to victims as soon as possible," Relief and Resettlement Minister Maj. Gen. Maung Maung Swe told a press conference Tuesday. The appeal came less than a week ahead of the referendum on a military-backed constitution that the junta hoped would go smoothly in its favor, despite opposition from the country's feisty pro-democracy movement. However, the disaster could stir the already tense political situation. A military transport plane flew from Bangkok to Yangon on Tuesday with emergency aid from Thailand while a number of other countries and organizations said they were prepared to follow. The United States, which has slapped economic sanctions on the country, said it likewise stood ready, but that a US disaster team must be invited into the country. "Our biggest fear is that the aftermath could be more lethal than the storm itself," said Caryl Stern, who heads the UN Children's Fund in the United States. UNICEF said it had dispatched five assessment teams to three of the affected areas and lifesaving supplies were being moved into position. Other countries, from Canada to the Czech Republic and Singapore, reacted quickly to the crisis with pledges of aid. The European Commission was providing US $3.1 million in humanitarian aid while the president of neighboring China, Hu Jintao, promised assistance without offering details. The diplomats said they were told Myanmar welcomed international aid including urgently needed roofing materials, medicine, water purifying tablets and mosquito nets. The Thais were sending a shipment of supplies. The appeal for assistance was unusual for Myanmar's ruling generals, who have long been suspicious of international organizations and have closely controlled their activities. The wife of the US president said her country was ready to pump aid into Myanmar for recovery efforts, but that the ruling junta must accept a US disaster response team. First lady Laura Bush, who has been the administration's chief voice on human rights and political conditions in Myanmar, faulted the junta for proceeding with the constitutional referendum, and criticized government leaders for not sufficiently warning citizens about the storm. "We know already that they are very inept," she said. There was little sign of official efforts to repair the damage in Yangon, but the worst-hit areas were in the countryside, now largely inaccessible by road because of the storm damage. "The combination of the cyclone and the referendum within a few days of each other makes an angry population angrier and vulnerable and makes the political situation more volatile" than it has been since last year's massive pro-democracy demonstrations, said Monique Skidmore, a Myanmar expert at Australian National University. At least 31 people were killed and thousands more were detained when the military cracked down on peaceful protests in September led by Buddhist monks and democracy advocates. The government had apparently taken few efforts to prepare for the storm, which came bearing down on the country from the Bay of Bengal late Friday. "The government misled people," said Thin Thin, a grocery story owner in Yangon. "They could have warned us about the severity of the coming cyclone so we could be better prepared." Yangon was without electricity except where gas-fed generators were available and residents lined up to buy candles at double the usual price. Most homes were without water, forcing families to stand in long lines for drinking water and bathe in the city's lakes.