UN Secretary-General Ban Ki-moon said he is hopeful "a turning point" had been reached in tackling Myanmar's cyclone crisis as an international conference convened Sunday to pledge funds for some 2.4 million survivors in need of aid. The one-day, 52-nation conference began on a note of optimism following promises by the ruling junta that foreign aid workers could enter the most devastated areas from which they have been banned since the cyclone struck three weeks ago. "I hope this marks a turning point in tackling the challenges facing this country," Ban told some 500 delegates as the conference convened with a minute of silence for the dead. But he said international relief workers and medical teams from neighboring countries must have "unhindered access to the areas hardest hit by the disaster." Prime Minister Lt. Gen. Thein Sein, shedding his military uniform for the sarong-like "longyi" and traditional jacket, said international aid "with no strings attached" was welcome but only civilian vessels could take part in the aid operation. "Relief supplies can be transported by land, air or sea. But if relief supplies have to be transported by water, civilian vessels can come in through Yangon port," he said. U.S., British and French warships, loaded with humanitarian supplies, have been cruising off Myanmar's coast. But last week, state-media said they would not be allowed into the country, citing fears of an American invasion to snatch the country's oil supplies. Thein Sein, saying that 3,200 tons of humanitarian supplies have already been delivered from abroad, presented a long list of urgent needs, including temporary shelters, rice seeds, fertilizer, fishing boats and new salt factories. Ban estimated the relief operation would last at least six months. "There is good reason to hope that aid to the worst affected areas of Myanmar will increase significantly in the coming days. These needs must be funded, immediately," he said. Myanmar's military regime was expected to call for $10.7 billion in foreign funds. But donors were unlikely to dig deep into their pockets until they actually gain access to devastated regions from which foreigners had been earlier banned. Several Western diplomats stressed aid by their countries would only be given if Myanmar carries through on its promises. Washington's representative, US Deputy Assistant Secretary of State Scot Marciel, said the United States was prepared to offer much more than the $20.5 million already donated. But the offer is on condition that international disaster experts are allowed to thoroughly assess conditions in affected areas to determine how best to help the victims. Bert Koenders, the Dutch minister for development cooperation, told The Associated Press: "The reason we came is to support Ban Ki-moon. That's the reason why many ministers came here. We're all very positive about what he has agreed with the government leader here, but also skeptical because you have to see the facts on the ground." After weeks of stubbornly refusing assistance, Myanmar's ruling generals told the United Nations they were now willing to allow workers of all nationalities to go into the devastated Irrawaddy delta to assess the damage. The ability to make such assessments will be essential in winning aid pledges from potential donors in Yangon, Myanmar's largest city. And some agencies voiced concern about how the junta would implement the agreement. Myanmar's generals have a long history of making promises to top UN envoys, then breaking them when the international spotlight on their country fades. The world body has repeatedly failed to convince the military to make democratic reforms and to release opposition leader and Nobel laureate Aung San Suu Kyi, whose five-year period of house arrest expires this week. Nyan Win, spokesman for Suu Kyi's National League of Democracy, said Sunday there has been "no sign at all" that she would be released. He said a decision on whether to free her or continue her detention would probably come Monday. Ban appeared to sideline political issues, saying, "We must think about people just now, not politics." An estimate released Saturday by the UN said of the total 2.4 million people affected by the storm, about 42 percent had received some kind of emergency assistance. But of the 2 million people living in the 15 worst-affected townships, only 23 percent had been reached. The United Nations has launched an emergency appeal for $201 million. That figure will likely increase further once disaster relief experts are able to survey the Irrawaddy delta. So far, the UN has received about $50 million (in contributions and about $42.5 million in pledges in response to the appeal, said Stephanie Bunker, spokeswoman for the UN Office for the Coordination of Humanitarian Affairs. Aid agencies said much needs to be clarified from Ban's meeting, ranging from logistical issues about when aid workers' visas will be granted to how long they will be allowed to stay in Myanmar and where they can work. Official estimates put the death toll at about 78,000, with another 56,000 missing. Myanmar has estimated the economic damage at about US$11 billion. The cyclone destroyed thousands of schools, hospitals and houses, millions of acres (hectares) of rice fields and killed vital livestock as well as fisheries. Besides reconstruction, the regime says it also wants to construct a sea wall that would protect coastal villages. The restoration of agriculture in the Irrawaddy delta, the country's rice bowl, is a high-priority concern. "Only a few weeks remain until the rice planting season begins," Ban said. "Millions of people depend on this next harvest, at a time when food prices are soaring around the world. A failure to deal with this problem today will immeasurably compound our problems tomorrow."