YANGON, Myanmar — Relief supplies from the United Nations began arriving in Myanmar Thursday, but U.S. military planes loaded with aid were still denied access by the country’s isolationist regime five days after a devastating cyclone.

The military junta also continued to stall on visas for U.N. teams seeking entry to ensure the aid is delivered to the victims amid fears that lack of safe food and drinking water could push the death toll above 100,000.

Two airplanes carrying high-energy biscuits, medicine and other supplies arrived in Yangon, and two others were to follow, U.N. officials said. The planes had waited for the last two days while the world body negotiated with the military regime to allow the material into the Southeast Asian nation.

In Yangon, the cyclone blew off the roof of Myanmar opposition leader Aung San Suu Kyi and snapped the electricity connection to her dilapidated lakeside bungalow, where she is under house arrest, a neighbor said.

The Nobel Peace Prize laureate has no generator and is using candles at night, said the neighbor, who spoke on condition of anonymity because of the sensitivity of the subject.

U.S. Ambassador to Thailand Eric John told reporters that U.S. and Thai authorities earlier believe they had permission from Myanmar to land U.S. military C-130s. But Myanmar officials later made it clear that this was not the case.

John said it was not clear if they had reversed an earlier decision or if there was a misunderstanding.

Thailand Prime Minister Samak Sundaravej offered to negotiate on Washington’s behalf to persuade the junta to accept U.S. aid.

The U.S. military, meanwhile, sent more humanitarian supplies and equipment to a staging area in Thailand. A C-17 transport plane with water and food landed Thursday, joining the two C-130s in place, Air Force spokeswoman Megan Orton said at the Pentagon. Another C-130 loaded with supplies was on its way, she said.

The Navy also has three ships participating in an exercise in the Gulf of Thailand that could help in any relief effort, including an amphibious assault ship with 23 helicopters aboard.

The Navy was sending helicopters from the USS Essex to the staging area in Thailand, a defense official said Thursday on condition of anonymity because he was not authorized to speak on the record.

After they finish off-loading the helicopters, the Essex and the USS Juneau were expected to steam around the Malay Peninsula to be in a position closer to Myanmar.

The USS Harpers Ferry and a destroyer, the USS Mustin, were expected to head toward Myanmar on Friday, the official said.

Within days of the 2004 Indian Ocean earthquake and tsunami, the U.S. military sent dozens of Navy ships and some 15,000 military personnel to deliver food, tents and medical care to victims. It was the biggest U.S. military operation in Southeast Asia since the Vietnam war.

The government and the U.S. private sector also committed over $1.5 billion in aid.